Prompt to overwrite in Windows Save As dialog

Add OFN_OVERWRITEPROMPT so the dialog will prompt before overwriting an existing file.
Remove the OFN_FILEMUSTEXIST flag, which works only with Open dialogs.
TM: simplify match test for current tag
TM: don't needlessly duplicate array when searching for current tag
Cleanup Plugin Manager dialog

Merge "Name" and "Description" columns, and move plugin details to
tooltips.
Use rst2pdf instead of rst2latex and pdflatex to generate PDF manual
Waf: correctly link libm as required
Adding while to list of SQL keywords
Merge pull request #249 from b4n/b4n/waf/link-libm

Waf: correctly link libm as required
Try to fix some duplicated accelerators inside Edit->Commands
Update tooltip string for check_cmdline_new_files
Update open string on filebrowser plugin to make clearer, that the file will be opened in Geany
Hide column headers in plugin manager dialog

They are not very useful and waste both vertical (the headers
themselves) and horizontal (first column wider because of title)
screen space.
Merge branch 'plugin-dialog-cleanup'
Merge branch 'b4n/use-rst2pdf'
Fix Waf build for recent Doxyfile changes

Recent changes to Doxyfile.in added new placeholders the build system
has to replace, and Waf recognized them but failed, not knowing what to
replace them with.
Fix UI updating after loading a project

When loading a project and focusing the last document, the UI wouldn't
get properly updated for the displayed file -- because for performance
reasons we disable notebook page switch handlers when loading session
files.  Fix this by synthesizing a notebook page switch event when done
loading.
Update of Japanese translation
CSS: fix mappings to non-existing styles
CSS: remove some pseudo elements listed as pseudo classes
Disable commenting out blank lines by 'Toggle line commentation'