Add information about built official documentation to README.md

don't allow empty dimension for ARRAY types

ignore built documentation

manual: add untranslated po files for French and Korean

build missing pot files, when building HTML documentation

fix some typos

Changed title of new project dialog from:
Choose a project
to
Choose an empty directory for new project

Changed title of New Project dialog
from
Chose a project
to
Choose an empty directory for new project

skip hidden files and directories on permission check

To fix problems with git, because .git subdirectory contains
read-only repository objects.

change structure of filename for bug reports in Beremiz and
PLCOpenEditor so bug reports could be easily sorted by name

fix target Xenomai missing functions

update messages.pot and messages.po

mki18n.py: generate messages.po (contains English strings in msgstr)

This po file is necessary because Transifex translation platform
automatically can only import PO files. Usually messages.pot is
enough.

add to i18n/README forgotten commands to add some XML schemes as source
for strings and update app.fil

Backout commit 92537ed because of writing localized string in node *.xml file