fix typos

[ghost]

REGRESSION-SUITE TODO TODO.CTKlight doc/c2hs.xml src/C2HS/C/Names.hs src/C2HS/C/Trav.hs src/C2HS/CHS.hs src/C2HS/CHS/Lexer.hs src/C2HS/Gen/Bind.hs src/C2HS/config.c src/Main.hs src/System/CIO.hs src/Text/Lexers.hs

---

unattended to

$ cd c2hs/tests/bugs
$ sed -i 's/existng/existing/g' issue-75/sndfile.h
$ sed -i 's/lenght/length/g' issue-75/sndfile.h
$ sed -i 's/descritor/descriptor/g' issue-75/sndfile.h
$ sed -i 's/forseeable/foreseeable/g' issue-75/sndfile.h
$ sed -i 's/availlable/available/g' issue-82/include/Availability.h
$ 

have you an opinion on anding and headder in the below

$ grep 'anding a' c2hs/src/C2HS/Gen/Bind.hs
              -- in particular, shifting right followed by anding a mask is
$

$ grep headder c2hs/src/C2HS/C/Names.hs
nameAnalysis headder  = do
                          (ac', _) <- runCT (naCTranslUnit headder) emptyAttrC ()
$