(flymake-get-cleanup-function): Default to flymake-simple-cleanup.

(flymake-get-cleanup-function): Default to flymake-simple-cleanup.
(flymake-allowed-file-name-masks): Use this new default.
All the functions are now called in the right buffer rather than
passing the buffer as argument.
(flymake-process-sentinel): Switch to buffer before calling cleanup.
(flymake-parse-err-lines): Remove redundant buffer arg.
(flymake-get-program-dir): Comment out unused function.
(flymake-start-syntax-check, flymake-start-syntax-check-process):
Remove redundant buffer argument.
(flymake-get-real-file-name, flymake-simple-java-cleanup)
(flymake-simple-cleanup, flymake-master-cleanup): Remove buffer arg.