Added syntax highlighting support for # hash comments in AppleScript

AppleScript [now supports](https://developer.apple.com/library/mac/documentation/applescript/conceptual/applescriptlangguide/conceptual/ASLR_lexical_conventions.html#//apple_ref/doc/uid/TP40000983-CH214-SW8) single-line comments delimited either by two dashes `--` or the hash symbol `#`. Since previously the AppleScript language definition for Sublime highlighted only the former, this pull request adds support for the latter.

An example of an AppleScript source file that contains all comment varieties can be found [here](https://github.com/qlassiqa/qWorkflow/blob/master/uncompiled%20source/q_workflow.applescript).