Toplevel: catch exceptions during serialization

Exceptions can also happen during serialization, but serialization is
outside the try/with loop, so merlin process would die.
type-enclosing: fix out of bound error
emacs: minor commit

Moved Ronan's code with the rest of the error reporting code.
Merge pull request #100 from lehy/master
emacs: rename merlin-*-phrase to merlin-phrase-*
emacs: minor fixes in error reporting functions
completion: fix test of suffix for record fields
parser: fix printing of malformed module errors
vim: fix printing of error messages
merlin-typers: sync
Makefile: allow to build all versions with one target
merlin-typers: sync
emacs: use markers rather than points for error locations
vim: fix merge failure, remove dead code
emacs: cleanup, documentation update