tests: Turn sentence test into a shell script
For consistency with other tests. Also it fixes a test failure when
built with --disable-shared, since LOG_COMPILER set to $(SHELL) doesn't
recognize binary executable.
* gettext-tools/tests/Makefile.am (TESTS): Rename 'sentence' to
'sentence-1'.
(check_PROGRAMS): Rename 'sentence' to 'sentence-1-prg'.
(sentence_1_prg_SOURCES): Rename from 'sentence_SOURCES'.
(sentence_1_prg_CPPFLAGS): Rename from 'sentence_CPPFLAGS'.
(sentence_1_prg_LDADD): Rename from 'sentence_LDADD'.
* gettext-tools/tests/sentence-1: New file.
* gettext-tools/tests/sentence-1-prg.c: Rename from sentence.c, move the
test data to sentence-1.
* gettext-tools/tests/.gitignore: Ignore sentence-1-prg.
