Fixed handling of INT32_MIN in s72int and INT64_MIN in s72intw

int2s7 and intw2s7 both encode the lowest possible integer value with the
output code 1, which was converted to 0 by s72int and s72intw.  Fixed the
latter so they output the correct value instead.  Also added some test code
to exercise these functions, including testing all the extreme values.



git-svn-id: svn://svn.code.sf.net/p/staden/code/staden@3596 ba6f2710-ca9f-427c-89d3-5bf716dbc8e1
Changed flags in contig_t struct from tg_rec to uint32_t

Done to match what is stored in the database.


git-svn-id: svn://svn.code.sf.net/p/staden/code/staden@3597 ba6f2710-ca9f-427c-89d3-5bf716dbc8e1