science/mpqc: Fix library dependencies

Problems in this port caused the science/libghemical breakage
(it was labeled as DEPRECATED).

Two major fixes:

• Fix the unknown 'backtrace' symbol: libexecinfo.so dependency was missing for libSCmisc.so
• Fix broken libint.so: -L${LOCALBASE} was missing for libSCcints.so and libint.so was just ignored and effectively missing

These two problems were previously attempted to be patched with "-Wl,--as-needed -lexecinfo -Wl,--no-as-needed"
but this didn't work. So this line is now removed from Makefile, and proper flags are supplied to
the link commands.

Other port changes:

• Take maintainership
• Add missing RUN_DEPENDS for wish:x11-toolkits/tk-wrapper
• Add CONFLICTS_BUILD
• Fix MPICH_LIB_DEPENDS to point to net/mpich2
• patch the 'wish' path in configure