Add unite.sh which can create an amalgamation of header and source files.

This commit effectively increases the possible productivity with whitedb, as well as making the environment as readily available as SQLite3 (somewhat).

By combining the headers into one file, and source files into one file, third party developers can effectively copy these files into their code base, and easily use the entire library.
Obviously comforming to the license of both YAJL and WhiteDB is a requirement of doing so, but this enables future open source GPL licensed software to benefit vastly from WhiteDB, even if (some) performance hit can be taken [citation_needed].

(I did not notice any performance hit when compiling Examples/speed/speed10.c with a modified whitedb.h inclusion, as opposed to the latest "master" (4555d5a0c77929ff926c2a0fdf7802d2a2ef9b03 as of the time of writing), however this still needs testing).