Package for Haxelib, Support "-errorpage out/index.html" while compiling

4 main things in this pull request:

* A few small path fixes (needed for livehaxe to work on Ubuntu)
* Added an "-errorpage" option that displays a "Currently Compiling" page and then an error page if there were errors.
* Added / edited to prepare this for pushing to haxelib.  
* Small fix for haxelib's first argument weirdness