Added HTML5 self-closing tags

http://www.w3.org/TR/html-markup/syntax.html#syntax-elements
Fix custom icons on Windows

Install all icons on Windows, as well as a theme index because the
system doesn't have one and one is required.

Also install the theme index on non-Windows, although it shouldn't
be necessary because the system is likely to provide one.
Don't install themes index on non-Windows

On non-Windows, the icons are installed on the system's icon directory,
so installing our index.theme might override the system's one.  Since
it's highly unlikely the theme index is missing on non-Windows, just
don't install it.
Revert incomplete Asciidoc filetype commit.

This reverts commit da78a44a1cfeb753e0d06d7175e882f508ad9788.
Add Asciidoc filetype

Add a filetype for Asciidoc with symbol parser, but not styling.
Correct Names of levels

Make the top level the Document, make lower levels translatable
although they do not normally show in Symbols pane.
Fix indent setting

Asciidoc requires single line comments to be at the start of the line
so do not want indent.
Comment future fixes/additions

Note where Asciidoc features need to be supported that would
prevent code sharing with other markup parsers.
Update po/he.po

Update Hebrew translator
Update of Hebrew translation
Merge pull request #95 from YosefOr/patch-7

Update Hebrew translator
Early NEWS update
Detect SCons configuration files as Python

SCons configuration files are plain Python, just without the .py
extension.
Ignore more build files
Add missing D keywords

Closes #3595187.
Print filename of failed plugin
Adding first version of Hindi translation
Update of Finnish translation
Added first version of Serbian translation
Replace ru_RU with simple ru inside credantials as we only have one Russiian translation