Typo fixes

+ User facing typos
+ trivial source comment typos
+ superflous double whitespace issues
+ found redundant comment typo
Found using `codespell -q 3 --skip="./build/wix/Localization,./res/translations,./lib" -I ../mixxx-whitelist.txt` where the contents of the whitelist were:
```
iff
freee
substract
```

122 files changed, 216 insertions, 216 deletions

diff --git a/build/appveyor/build_mixxx.bat b/build/appveyor/build_mixxx.bat
index ac1bc6f198..aa35591642 100644
--- a/build/appveyor/build_mixxx.bat
+++ b/build/appveyor/build_mixxx.bat
@@ -105,7 +105,7 @@ echo Could not find Qt %QT_VERSION% at "%QT_DIR%".
 exit /b 1
 )
 
-REM Everyting prepared. Setup the compiler.
+REM Everything prepared. Setup the compiler.
 if %MACHINE_X86% (
 call "%BUILDTOOLS_PATH%\%BUILDTOOLS_SCRIPT%" %COMPILER_X86%
 ) else (
diff --git a/build/depends.py b/build/depends.py
index 19dcec0c4e..c5c6efb2a2 100644
--- a/build/depends.py
+++ b/build/depends.py
@@ -561,7 +561,7 @@ class TagLib(Dependence):
                 "Could not find libtag or its development headers.")
 
         # Karmic seems to have an issue with mp4tag.h where they don't include
-        # the files correctly. Adding this folder ot the include path should fix
+        # the files correctly. Adding this folder to the include path should fix
         # it, though might cause issues. This is safe to remove once we
         # deprecate Karmic support. rryan 2/2011
         build.env.Append(CPPPATH='/usr/include/taglib/')
@@ -599,7 +599,7 @@ class FpClassify(Dependence):
     def enabled(self, build):
         return build.toolchain_is_gnu
 
-    # This is a wrapper arround the fpclassify function that pevents inlining
+    # This is a wrapper around the fpclassify function that prevents inlining
     # It is compiled without optimization and allows to use these function
     # from -ffast-math optimized objects
     def sources(self, build):
diff --git a/build/features.py b/build/features.py
index e96fad6062..683a6186ed 100644
--- a/build/features.py
+++ b/build/features.py
@@ -1131,7 +1131,7 @@ class Optimize(Feature):
                 optimize_level = Optimize.LEVEL_PORTABLE
 
             # Common flags to all optimizations.
-            # -ffast-math will pevent a performance penalty by denormals
+            # -ffast-math will prevent a performance penalty by denormals
             # (floating point values almost Zero are treated as Zero)
             # unfortunately that work only on 64 bit CPUs or with sse2 enabled
 
diff --git a/build/osx/OSConsX.py b/build/osx/OSConsX.py
index b4f196f3ab..4434288d12 100644
--- a/build/osx/OSConsX.py
+++ b/build/osx/OSConsX.py
@@ -207,7 +207,7 @@ def build_app(target, source, env):
 
     def relative(emb):
         "compute the path of the given embedded binary relative to the binary, i.e. @executable_path/../+..."
-        # assume that we start in X.app/Contents/, since we know neccessarily that @executable_path/../ gives us that
+        # assume that we start in X.app/Contents/, since we know necessarily that @executable_path/../ gives us that
         # so then we only need
         base = os.path.abspath(str(installed_bin))
         emb = os.path.abspath(emb) #XXX is abspath really necessary?
@@ -233,7 +233,7 @@ def build_app(target, source, env):
 
 
 
-    #Workarounds for a bug/feature in SCons such that it doesn't neccessarily run the source builders before the target builders (wtf scons??)
+    #Workarounds for a bug/feature in SCons such that it doesn't necessarily run the source builders before the target builders (wtf scons??)
     Execute(Mkdir(contents))
     Execute(Mkdir(MacOS))
     Execute(Mkdir(frameworks))
@@ -250,7 +250,7 @@ def build_app(target, source, env):
         locals[ref] = (path, embed_lib(path))
 
     plugins_l = [] #XXX bad name #list of tuples (source, embed) of plugins to stick under the plugins/ dir
-    for p in env['PLUGINS']: #build any neccessary dirs for plugins (siiiigh)
+    for p in env['PLUGINS']: #build any necessary dirs for plugins (siiiigh)
         embedded_p = os.path.join(str(plugins), os.path.basename(str(p)))
         plugins_l.append(  (str(p), embedded_p)  )
 
diff --git a/build/osx/otool.py b/build/osx/otool.py
index e821bb4414..f1d292533d 100644
--- a/build/osx/otool.py
+++ b/build/osx/otool.py
@@ -165,7 +165,7 @@ def embed_dependencies(binary,
 
 		#sometimes the todo list will have redundant items placed on it; in the case that the items are named the same that could be avoided by relying on set() semantics
 		#however there are many equivalent ways to name files in Unix, so we have to check here after getting abspath
-		#proof that this makes the algorithm terminate: we record the absolute path to the file; even if there are multiple abspaths to one file (as can happen with symlinks sometimes) each differnt path means a different symlink file, of which there are only a finite number (since it's a finite disk)
+		#proof that this makes the algorithm terminate: we record the absolute path to the file; ev