Make all the easy updates. There are still quite a few to do, but in
doing these ones I can see that syntastic#makeprg#build() needs to
accept a few more options. Namely:
* "postargs" that appear after the filename
* "tail" that appears after everything - used for things like
redirecting output and piping to grep/sed/etc
* the filename itself - only the java checkers needed this since they
specify the directory of the file to check as well
There are still a few other things to do as well:
* remove the options from the checkers that are now provided by
syntastic#makeprg#build implicitly - i.e. the checker exe and args.
* also, we need to doc the above implicit checker options
If no syntax errors are found, `gofmt -l % 1>/dev/null` prints the file
name to STDOUT, which is redirected to /dev/null. Less to parse for
syntastic!
If errors are found, they are written to STDERR.
This invocation does not alter the source code, which has been indicated
in the comments.
