Compiler warning in prcserror.h

[Kaz Nishimura]

./include/prcserror.h:507:63: warning: friend declaration ‘std::ostream& operator<<(std::ostream&, const omanip<TP>&)’ declares a non-template function [-Wnon-template-friend]
./include/prcserror.h:507:63: note: (if this is not what you intended, make sure the function template has already been declared and add <> after the function name here)

[Kaz Nishimura]

Added a function template to fix issue #13.

→ <<cset aa2d16de26fe>>