nspr: fix for mock build

[Amorilia]

Hi everyone,

Here's a fix for the build problem for nspr in mock:

http://github.com/amorilia/fedora-mingw/commit/1c143a5840bb15b11098edb7130ec0aace6a54d2

It seems that the problem goes back all the way to AC_PROG_CC: when
wine is installed, apparently AC_PROG_CC (mistakenly?) sets
cross_compiler to false.

Additionally, here's a sync of the spec file with the native fedora
one, and a few extra build patches:

http://github.com/amorilia/fedora-mingw/commit/19af2a48f6d2cc90009c581a7e8aa97c8171d7ab
http://github.com/amorilia/fedora-mingw/commit/629eb75b24e1755c92041b614b4012e14b9554ff
http://github.com/amorilia/fedora-mingw/commit/44031e8cf4d0149debeb97c0c833d4634be42461

Although the tests build, when running them under wine, many fail. I
haven't investigated this further.

I don't plan to work on this anymore for the time being, so I'm simply
throwing these patches here in case someone else would be interested.
For quick reference, full spec file and patches:

http://github.com/amorilia/fedora-mingw/tree/master/nspr/

Yours,
Amorilia