Improve configsys option parsing

Up until now all the options in the config system have only been
able to take one word (or one string with no spaces) as a parameter.
This update improves it so it takes everything after the = up until
the end of the line (or the first #) as the parameter.
Merge pull request #19 from alexfru/master

Smaller C: Improve pointer initialization
Include files modified for compatibility with SmallerC.
Fixed bug in C preprocessor: buffer size reduced to avoid allocation failure.
Added option -v for smlrc.
New example stdarg.c: a demo of function with variable arguments.
Smlrc: option -v moved to target-dependent part.
Fixed bug in simulator: read from incorrect file descriptor when
the second SD card not configured.