Add Apex System Method Completions

Updated Apex System Method completions per
https://github.com/joeferraro/MavensMate-SublimeText/issues/157
Completion Matching

* Better regex tests
* Variable in function signature
* Variable created in iterator
* Check for variable on right of equals
Regex fixes, IGNORECASE
Apex Trigger Context Variables

Adding trigger context variables to code completions.
Apex System Objects, annotations, keywords

Additional Apex system code completions, custom handling of Exceptions
and DmlException/EmailException. Adding missing keywords.
Merge pull request #162 from doublesharp/patch-apex-system-completions

Add Apex System Method Completions