add support for operator symbol anchors to inferior-haskell-find-haddock

For operator anchors encode operator names into sequence of -<ascii-code>-
strings for each operator character, as haddock does. Also supply anchor for
local paths.
tweak font lock: treat # as part of symbol, highlight operators with dedicated face
change repl buffer name to "ghci"
fix constructor fontification
add chs extension support
regexp-related tweaks
enhance indentation error reporting
allow haskell-program-name to be list of arguments
tweak fontification: remove redundant reservedsym entries, split operators into constructor and non-constructor ones, refire operator regexp to not match "@", make operator fontification override previously applied fontification
add type family/type instance keyword fontification
use haskell-regexen regexps
font lock "data" type families in addition to "type" type families
highlight compilation errors in Alex and Happy files