major updates to syntax checking: multiple errors supported

[jasonwilliams]

• A new filename so its not so ambigous
• Fixed errors on textCommand (now the plugin checks before trying to display a popup)
• Now using the new sublime popup API (https://forum.sublimetext.com/t/dev-build-3070/14538)
• The error code is now a link to the correct page on the rust website
• Now supports multiple errors!
• Now highlights the erroneous text causing the error, as well as displaying a dot in the gutter
• tidied up code
• A check which requires sublime >= 3113 to prevent crashes on Sublime Text 2

As you can see getting the tooltip to appear is a bit tricky, im trying to see if Sublime has a better option
Would be nice to have some beta testers for this

[jasonwilliams]

[VelocityRa]

Nice! Should make a new project, the maintainer of this one doesn't seem to merge an PRs...
Guess people can just use "Package Control: Add Repository" to use your fork.

[jasonwilliams]

I will close this PR, as the improved work was done in:
#87