Merge pull request #161 from l/translation_ja

core: update Japanese translations
core: make argument "errors" optional in function string_replace_with_callback
core: updated polish translations
doc: update Polish auto-generated files
core: separate new features and bugs fixed in ChangeLog
tests: add tests of function string_replace_with_callback
debian: link against libgcrypt20-dev and libgnutls28-dev
doc: add missing file "tests.cpp" in developer's guide
tests: don't install binary "tests" with autotools
tests: add partial tests of functions hashtable_set*
tests: add tests of function string_split_shell
tests: fix memory leaks
tests: read WeeChat command line arguments in environment variable "WEECHAT_TESTS_ARGS"
Version 1.0

Yay! \o/
Version 1.1-dev
tests: fix memory leak in tests launcher
core: fix asciidoc style in ChangeLog
core: install extra files for Cygwin in share/doc/weechat
core: add gettext-devel dependency for Cygwin packaging
aspell: fix crash with command "/aspell addword" if no word is given (closes #164)