Changed the indentation behavior such that an extra level of
indentation is added after a line containing a ( or { that is
not closed on the same line instead of aligning to the unclosed
( or {. This is consistent with how `go fmt` formats source code.
Added regression tests.
When indenting on newline in Go files, only remove trailing whitespace
on the previous line and copy indentation of the previous line if in
comment context.
Added regression tests.
