Implement user actions for font resize (#625)

Adds support for font resizing at run-time. Three new actions are
introduced:

* IncreaseFontSize - Increases current font size by 1.0
* DecreaseFontSize - Decreases current font size by 1.0
* ResetFontSize - Resets font size to that specified in the
  configuration.

The stock config files have example configuration for each which should
match gnome-terminal. For convenience, the config entries are:

    - { key: Key0,     mods: Control, action: ResetFontSize    }
    - { key: Equals,   mods: Control, action: IncreaseFontSize }
    - { key: Subtract, mods: Control, action: DecreaseFontSize }

1 files changed, 2 insertions, 3 deletions

diff --git a/src/renderer/mod.rs b/src/renderer/mod.rs
index 9ce690ca..9e6036d4 100644
--- a/src/renderer/mod.rs
+++ b/src/renderer/mod.rs
@@ -29,7 +29,7 @@ use gl;
 use index::{Line, Column, RangeInclusive};
 use notify::{Watcher, watcher, RecursiveMode, DebouncedEvent};
 
-use config::{self, Config, Delta};
+use config::{self, Config, Font, Delta};
 use term::{self, cell, RenderableCell};
 use window::{Size, Pixels};
 
@@ -170,12 +170,11 @@ pub struct GlyphCache {
 impl GlyphCache {
     pub fn new<L>(
         mut rasterizer: Rasterizer,
-        config: &Config,
+        font: &Font,
         loader: &mut L
     ) -> Result<GlyphCache, font::Error>
         where L: LoadGlyph
     {
-        let font = config.font();
         let size = font.size();
         let glyph_offset = *font.glyph_offset();