doc: maintain po with no-location

see http://www.clear-code.com/blog/2013/11/14.html
Merge pull request #135 from kenhys/po-with-no-location

doc: maintain po with no-location
doc: ignore po files for editing use
doc: update file list
doc: use po files without location information
doc: use po files without no location

TODO: remove '# hash' too.
doc: drop message hash from po files
doc: drop message hash from po files
travis: enable CMake build again
cmake: add missing GRN_LOCK_TIMEOUT entry
travis: disable CMake build again

Because CMake on Travis CI is old...
doc: add 3.1.2 entry
doc: don't update only po header fields
doc: fix a typo
windows: fix conflicted declaration in MinGW environment

This change fixes following error:

  /usr/lib/gcc/i686-w64-mingw32/4.6/../../../../i686-w64-mingw32/include/stdio.h:339:5:
  error: previous declaration of 'int _snprintf(char*, size_t, const
  char*, ...)' with 'C++' linkage
  /usr/lib/gcc/i686-w64-mingw32/4.6/../../../../i686-w64-mingw32/include/stdio.h:532:110:
  error: conflicts with new declaration with 'C' linkage
windows: fix conflicted declaration in MinGW enrironment

This change fixes following error:

  /usr/lib/gcc/i686-w64-mingw32/4.6/../../../../i686-w64-mingw32/include/stdio.h:350:5:
  error: previous declaration of 'int _vsnprintf(char*, size_t, const
  char*, char*)' with 'C++' linkage
  /usr/lib/gcc/i686-w64-mingw32/4.6/../../../../i686-w64-mingw32/include/stdio.h:534:121:
  error: conflicts with new declaration with 'C' linkage
doc: update po
doc development/en: use "Groonga" notation for English
Merge pull request #151 from cosmo0920/use-Groonga-notation-development-en

doc development/en: use "Groonga" notation for English users

Patch by cosmo. Thanks!!!
test: fix wrong location

It is a test for --scorer not --filter.