Add: Scheme highlight rules
new file:   lib/ace/mode/scheme.js
new file:   lib/ace/mode/scheme_highlight_rules.js
Update Scheme mode.
modified:   demo/kitchen-sink/doclist.js
modified:   demo/kitchen-sink/modelist.js
new file:   lib/ace/mode/_test/tokens_scheme.json
modified:   lib/ace/mode/scheme_highlight_rules.js
Add scheme.scheme

new file:   demo/kitchen-sink/docs/scheme.scheme
Fixed: keyword can't be colored

modified:   demo/kitchen-sink/docs/scheme.scheme
* fix typo
modified:   lib/ace/mode/scheme_highlight_rules.js
* remove '() since it's hard to parse and trivious for coloring.
* keyword and constant coloring fine now.
Fixed keywords and constant parse bug

Fixed: 'minus' shouldn't be a delimiter
Fixed: '\t' shouldn't be included in keword-type
Fixed: test case for scheme
Merge pull request #1231 from NalaGinrut/master

Add Scheme mode
update scheme mode to work with new tokenizer