checkpoint, there's a bug somewhere in compiling statements
but this change simplifies api such that only infinisql_api.h needs
to be included by stored procs
checkpoint. broken regression.pl, not sure when introduced.
main changes this commit are simplifying api to include a single header,
and to revert parser.yy changes described in issue 19.
fixed regression test, had to do with range map deletion
change api header from infinisql_api.h to infinisql.h
remove all infinisql_ prefixes from header filenames