Gerber export fixed in Windows

Gerber export now works in Windows, even if no "zip" executable is available. (We use PowerShell's Compress-Archive instead.)

BOM improvements

Major improvements to CPCB BOM handling
Lots of minor improvements and bugfixes
Many new symbols and footprints

v0.1.6a

Ready to release v 0.1.6 for windows

Initial public release of CSchem and CPCB

CSchem and CPCB are a pair of programs for drawing electronic circuit diagrams and laying those circuits out on a printed circuit board. More information, binaries, and user guides are at http://danielwagenaar.net/cschem.