(I25) Fix Xproto deprecation warnings

I made the ELFlagFocus and ELFlagSameScreen fields in enterLeave
__gshared const int because it was the closest to a C representation of
the different options available.
use enum to represent #define in Xproto.d
fix file header
Merge pull request #26 from growlercab/issue_25_xproto-deprecations

(I25) Fix Xproto deprecation warnings