lavu/math: fix than/then typo, and add a comma.
lavf/mpegtsenc: fix missing word in error message.
Replace references to "que" with the appropriate word.

"que" sounds like a slang word to me. This commit renames a few
variables, fix the comments and the logging messages (sometimes along
with small other typo fixes).
tiff: print error for old style LZW

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>