Previously, the last viewer set in `+latex-viewers` would take
precedence. The list is now reversed before applying changes so that the
first set has precedence.
The wrong hook variable was used to revert view buffers after compilation.
This incorrectly reversed the priority ordering of +latex-viewers. This
is an artifact from a rejected approach at short-circuiting
+latex-viewer, which was replaced with cl-block->cl-return.
Reported by @UndeadKernel
The +zathura, +skim, +okular and +pdf-tools module flags have been
removed in favor of +latex-viewers, which takes a list of symbols. Its
order determines the priority. The first viewer found on your system is
used.
If none of these viewers are found, it will fall back to
latex-preview-pane.
