Add control over database location

testsuite portability fixes

Update libtool versioning in preparation for release

Fix compiler warnings

Drop drive letter from path to razor root when RAZOR_ROOT set.

If the RAZOR_ROOT environment variable was set to eg., /root then on
Microsoft Windows we were trying to use paths such as /rootC:/Programs
which is obviously wrong. Instead we should drop the drive letter
giving paths of the form /root/Programs. Note that the drive letter is
_not_ migrated to C:/root/Programs: If a root of C:/root was desired
then RAZOR_ROOT would have been set to C:/root.

Remove INTLLIBS from librazor_la_LIBADD.

This partially reverts 611c84a3f4b4538a65d186050608c17adbf17770.
It's not clear what motivated the initial inclusion of INTLLIBS
here since the net effect is only seen in librazor.la and not
in razor.pc and librazor.la is not normally packaged. Certainly
neither the static nor the dynamic versions of librazor currently
use libintl. At best this would cause the linker to search a
static libintl for undefined symbols without finding any; at worse
it causes a static build of plover using librazor.la to fail if
no static version of libintl is installed.

Add secondary text to errors

Update gnulib

Start 0.5.7

Release version 0.5.6