One weird trick to speed up your imports.

Setting the `build.FindOnly` flag when calling `context.Import`
drastically speeds up parsing, especially when accessing remove file
systems (e.g.  nfs). Tests are still running and everything seems fine
so far, hopefully nothing relies on anything other than `p.PkgObj`, so
we should be fine.
Minor fixes to autobuild function.
Merge branch 'check_err' of https://github.com/tiziano88/gocode
Merge branch 'import_find_only' of https://github.com/tiziano88/gocode