Previously, UseLATEX.cmake was calling latex_needit for the
BIBLATEX_COMPILER variable. However, this variable was never set
because the FindLATEX module sets the BIBER_COMPILER variable instead.
Look for that variable.
Other minor changes include updating the documenting comments and calling
wantit rather than needit on the biber compiler just in case there are
latex installations without it.
The newest 3.* CMake versions may be missing in some distributions.
The most recent feature required by UseLATEX and its tests is
ced1d5eccd:
"Skip file-level dependencies on custom targets (#11332)". The commit is
included in the release version 2.8.4.
The following error messages are produced during compilation with
earlier CMake versions:
[100%] Built target UseLATEX_pdf
make[2]: *** No rule to make target `UseLATEX_pdf', needed by `UseLATEX_build/CMakeFiles/UseLATEX'. Stop.
Signed-off-by: Anatoly Borodin <anatoly.borodin@gmail.com>