cahman Haxe Manual Edits

Tried to clean, reorganize, and fill in some missing sections of the manual.

Added two required packages to HaxeDoc.tex : geometry and todonotes. They will have to be installed to build the tex file to a pdf. They came included with my LaTeX distribution, but YMMV.

I mostly developed with the pdf, so be on the lookout for incorrect formatting in the MarkDown files.

Added a few additional LaTeX commands to the MarkDown converter.

I'm a space-indent man myself, and only noticed the tab-indents after a few edits. I think I fixed them all, but if I messed up the spacing in some of the Haxe files, apologies.

Probably want to the change the repository README.md file...

Also added a few additional files to .gitignore