fits: improve, fix compilation on Solaris
fits: improve, fix compilation on Solaris

- include monetdb_config.h from the .c part (this probably resolves the
  problem seen on Solaris:
  http://monetdb.cwi.nl/testing/projects/monetdb/testweb/logs/39503:ca62c7fe7f3d/GNU-Solaris-sparc/make.html#l2498
- include necessary files only in .h part if this is necessary for
  declarations
- cosmetics

zyzyis/monetdb,zyzyis/monetdb,zyzyis/monetdb,zyzyis/monetdb,zyzyis/monetdb,zyzyis/monetdb,zyzyis/monetdb,zyzyis/monetdb,zyzyis/monetdb,zyzyis/monetdb