Moved clear() to base Message class.

Also added a makefile.
Fixed include for standard int types.
Added float support.

There are portability issues because of the use of htonl to
do byte swapping. Some platforms have different endian ints
and floats (e.g. Solaris on Sparc) so this code won't work
there.

Also fixed some missed name changed from the last commit.
Added as_dict() method to Message.
Changed as_dict to omit empty lists if terse=True.
Removed unwanted str() conversion in as_dict().
Added identical pure Python implementation.

Currently only supports a limited set of fields for
writing, and has no reading support.
Added fixed32 support.
Changed headers to compile on windows.
Added a README.