Merge pull request #157 from b4n/tableconvert/build-system-fix

tableconvert: Add new files to the Autotools build system
TableConvert: Some more Updates of documentation
Suppress error dialogs on startup

Instead of showing an error dialog on startup of Geany, suppress
the dialog and log the error only to the status messages.
This makes the error less obvious but is also less annoying
for an unconfigured or misconfigured Spell Check plugin.
Clean up icons on uninstall on Windows
Merge branch 'master' of https://github.com/geany/geany-plugins
Don't pass prebuilt strings directly as printf-format expected arguments
Plug memory leak
autotools: Enable subdir-objects as many plugins use sub-directory objects

Many plugins build object files from sub-directories, and when doing
this it is better to enable Automake subdir-objects option.  So, enable
it, as it is good and old enough anyway.
autotools: Don't allow undefined symbols in plugins when possible

Tell the linker not to allow undefined symbols in built plugins it
possible.

This avoids use of non-plugin API functions from plugins as using those
would lead to undefined symbols.  This works even as we don't link to a
"libgeany" or the like because Geany plugin API is hidden behind macros
indirection.
Merge pull request #159 from b4n/autotools-various

Two Autotools improvements
Adding new TableConvert files to list of translateable files
Small update of German translation
GeanyLaTeX: Remove unneeded debug output
tableconvert: Fix a typo in the build system (oops)