Hyperlink file and line number (#479)

Hyperlinks seem to be rendering with just the file path underlined, at
least in iTerm2, whereas the intention was for the file and
line-number to be rendered jointly (both underlined) as a hyperlink.
The link structure is

␛]8;;file-line-column:///Users/dan/src/delta/src/hunk_header.rs:114␛\␛[38;5;1msrc/hunk_header.rs␛[0m:␛[38;5;4m114␛[0m␛]8;;␛\:

1 files changed, 8 insertions, 2 deletions

diff --git a/src/delta.rs b/src/delta.rs
index f72302e4..81871068 100644
--- a/src/delta.rs
+++ b/src/delta.rs
@@ -350,7 +350,7 @@ impl<'a> StateMachine<'a> {
         self.painter.set_highlighter();
         self.painter.emit()?;
 
-        let (raw_code_fragment, line_numbers) = parse::parse_hunk_header(&self.line);
+        let (code_fragment, line_numbers) = parse::parse_hunk_header(&self.line);
         if self.config.line_numbers {
             self.painter
                 .line_numbers_data
@@ -367,8 +367,14 @@ impl<'a> StateMachine<'a> {
         } else if self.config.hunk_header_style.is_omitted {
             writeln!(self.painter.writer)?;
         } else {
+            // Add a blank line below the hunk-header-line for readability, unless
+            // color_only mode is active.
+            if !self.config.color_only {
+                writeln!(self.painter.writer)?;
+            }
+
             hunk_header::write_hunk_header(
-                &raw_code_fragment,
+                &code_fragment,
                 &line_numbers,
                 &mut self.painter,
                 &self.line,