Bug#884176: libxft-dev: Please mark the package Multi-Arch: same

[Hugh McMaster <hugh.mcmaster@outlook.com>]

Control: severity -1 important

I am raising this bug's severity to 'important', following advice from #887595.

Also, the lack of multi-arch awareness in this package blocks multi-arch support in 
libpango1.0-dev and libfontforge-dev. These packages, in turn, block multi-arch 
support in Wine (i.e. wine-development).

Marking libxft-dev as Multi-Arch: same will benefit many package, including 
packages depending on libpango1.0-dev and libfontforge-dev. So fixing
this bug is important.