Fix 131122_float_parsing_overflow.patch

Was from an early attempt:

https://github.com/ruby/ruby/commit/60c29bbbf6574e0e947c56e71c3c3ca11620ee15

which was later fixed:

https://github.com/ruby/ruby/commit/4cd481f031597b7b933af5d1a14a25c19841c0d1
Fix building on raring and saucy

pthread errors show up when building on raring and saucy. Rather
than fix it properly, am just enabling pthread on those distros.
Properly add 131122_float_parsing_overflow.patch
REALLY fix building on Raring and Saucy
Add patch to increase ruby patch version to 375
ruby1.8 (1:1.8.7.375-1bbox1)
build depends on lsb-release now