Independently check presence of latexmk and texify

MikTeX also ships latexmk, but without bundled perl interpreter.

texify state could be ignored if distro is set to anything else, but as it
doesn't hurt being marked "missing" for TeX Live setups, just always query both.

Author: deathaxe

latextools/system_check.py

@@ -296,7 +296,9 @@ def worker(self):
         # a list of programs, each program is either a string or a list
         # of alternatives (e.g. 32/64 bit version)
         programs = [
-            "latexmk" if not self.uses_miktex else "texify",
+            "perl",
+            "latexmk",
+            "texify",
             "pdflatex",
             "xelatex",
             "lualatex",