Merge pull request #21 from devoncarew/master

expose get/set showGutter
VirtualRenderer : implement OptionsProvider
pubspec : update
update to ace-builds 12.02.2013
release version 0.1.4+12.2.2013
0.1.5-dev+12.2.2013
VirtualRenderer : add `containerElement` and `mouseEventTarget` getters with doc and test
Mode : add `lua` to the _extensionMap
Mode : add `hs` -> `haskell` to the _extensionMap
Mode : add `svg` to the _extensionMap
Mode : add `scala` to the _extensionMap
Mode : add `hx` -> `haxe` to the _extensionMap
release version 0.1.5+12.2.2013
0.1.6-dev+12.2.2013
add `Annotation` class and add members `onChangeAnnotation`, `annotations`, and `clearAnnotations` to `EditSession`

+ doc and tests
_EditSessionProxy : return a mutable list from `get annotations`

Allow the caller to mutate the returned list; it is still not the actual
underlying javascript array, but it can be mutated and used to call `set
annotations`.
Add `_jsArray` and `_jsMap` utility functions and use them to optimize

These have better performance than `_jsify` and should be used for
simple List and Map conversions; complex json-like structures should
still be converted using `_jsify`.
CHANGELOG : add a note about the performance tuning
Annotation : construct directly from proxy object

we were doing an unnecessary _map conversion
EditSession : another performance tweak in `get annotations`

there is no need to _jsify each item in the array