VMF Library skeleton
Bits of brushes
Add some operator overloading to Property

- Lets you index subproperties, directly iterate, check equality, etc
Add more bits of the VMF lib
Add various comparison operators

== < > >= etc. They all ignore the property name, and can work between
Property - Property or Property - string.
Add a vector class

- Useful for property_parser data
- Immutable (so it can be dict keys if needed)
Output class functions.
Add some basic parsing to VMF class
More functionality
Solid parsing

It can now read ents and brushes correctly, but cannot export.
Test VMF
More vector class ops

>, <, ==, != with tuples (treats as vector), vectors (compares all) and
floats (compares magnitude). len(vec) returns integers only, use .mag()
in future.
Add find_ent to VMF class

- still buggy though.
Minor fixes
Lots of code for exporting files

Still todo:
- Export "editor" sections
- Make a lot of values actually save
- Export Visgroups, Cameras, many other bits.
Remove some debug stuff, fix gitignore
Correct indentation in export, export editor block

The export functions take an indent parameter, so other modules using
them can set what indent they need.
Add camera support, actually read metadata
Remove some debug code

Why did I even commit that?
Read and write quick-hidden entities