Add option to always break template declarations.

With option enabled (e.g. in Google-style):
template <typename T>
void f() {}

With option disabled:
template <typename T> void f() {}

Enabling this for Google-style and Chromium-style, not sure which other
styles would prefer that.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@182849 91177308-0d34-0410-b5e6-96231b3b80d8