v0.3.4

Release 0.3.4 of RGBDS:

• Reintroduce __LINE__ and DL.
• Fix NOT operator.
• Huge cleanup of the codebase.
• BANK() now works with the name of sections, and it can be used with no arguments to request the bank number where the code is located.
• Convert markdown files to reStructuredText, add CONTRIBUTORS.rst file.
• PUSHS and POPS also affect label scope.
• Improve some error messages.

Known bugs:

• WRAMX sections may not link correctly if a linkerscript is used.