x11-toolkits/wxgtk30: Support c++11 over c++0x, plus DragonFly
The wxgtk30 port will use TR1 headers if the capability is detected.
These TR1 functions were experimental and not included in the same form
in the final c++11 standard. This patch forcibly disabled TR1 support,
which requires the explicit setting of -std=c++11 in CXXFLAGS>
A private "exp-run" was performed, all 62 ports dependent on wxgtk2
successfully built before and after after the patch was applied on two
separate runs (FreeBSD 10 amd64 jail).
While here, remove the incorrect $PTHREAD_LIB setting and let it default
to -pthread. Also bring in the configure patch fragement from DragonFly.
Submitted by: marino
Approved by: maintainer (Chris Hutchinson)