core: remove multiple detections of pkg-config in configure.ac
ruby: add detection and fix compilation with Ruby 2.0 (patch #8209)

Now the search for Ruby is first performed with pkg-config and includes
detection of Ruby 2.0.
If not found, the old code for detection is used (for old distros or
old Ruby versions).

The specific test on Ruby 1.9.0 (to disable this version) has been
removed (1.9.0 was a dev/unstable version from 2007, quite old now).
Merge branch 'master' of git://git.savannah.nongnu.org/weechat into translation_ja
doc: update Polish translations and user's guide
Merge branch 'master' of git://git.savannah.nongnu.org/weechat into translation_ja
core: fix hotlist problems after apply of a layout (bug #41481)

This commit fixes a problem when computing the value of "num_displayed"
in all buffers. For merged buffers (with same number), the num_displayed
of each merged buffer must be incremented (and not only the current
active buffer).
core: fix typo in FindGnuTLS.cmake
Merge branch 'master' of git://git.savannah.nongnu.org/weechat into translation_ja
weercd.py: use /usr/bin/env in python shebang
core: fix apply of layout when buffers that are not in layout are before some buffers in layout

Now when a layout is applied, the buffers in layout are inserted/sorted
first in the new list. Then the other buffers (not in layout) are added
after this loop, and then they are added after all layout buffers.
Merge branch 'master' of git://git.savannah.nongnu.org/weechat into translation_ja