Allow user to configure path to tsc and tsserver

[hoanhtien]

For now we are shipping a TypeScript compiler and language service along with the plugin. However, some users have the tendency to stick with certain version of TypeScript and want to use that version in the plugin. It would be good to give them the ability to configure the TypeScript version they want to use.

Current state
Currently we have a setting "typescript_proc_file" to specify path to tsserver.js. There is no similar setting for tsc.

# retrieve the path to tsserver.js
# first see if user set the path to the file
settings = sublime.load_settings('Preferences.sublime-settings')
proc_file = settings.get('typescript_proc_file')
if not proc_file:
    # otherwise, get tsserver.js from package directory
    proc_file = os.path.join(PLUGIN_DIR, "tsserver", "tsserver.js")

Propose
There should be two settings "typescript_tsc_file" and "typescript_tsserver_file" with the following possible values:

• "plugin": use the tsc/tsserver shipped along with the plugin
• "global": use the tsc/tsserver in their PATH (most likely installed with NPM)
• path to executable tsc/tsserver (e.g. tsc.exe) or tsc.js/tsserver.js.

[wwwsevolod]

would be very helpful, trying to migrate back to sublime, and found that out, atom's typescript package is already able to do it (or may be they just using bleeding edge typescript like i do?).

current work around to some people is to delete files in this package on local computer and create symlink to your global files (works for me).

[yangmillstheory]

+1. I don't want to install tsc globally and use that same version in each separate typescript project I have.