Rewriting compilation-db [WIP]: Initiate testing & remove sources files in flags.
.eproject file: Remove the eproject-root from header search paths.
header-comp: Fix duplicates deletion
Irony: Rewrite flags management use one main variable irony-compile-flags.

- extra-flags + include-dirs are no longer differentiated
- pkg-config is removed
- -working-directory is added
- irony-header-directories-root has been replaced by
  irony-compile-flags-work-dir
- now header search paths are retrieviable with the function
  `irony-header-search-paths`, they deduced from irony-compile-flags
Mark eproject plugin as temporary broken.
Compilation DB: Rewrite plugin, create a menu a la Org-Mode export.
Compilation DB: Add Preferences item and fix 'c' command.
Find a better work-around around "missing 'stdarg.h'" error.
Compilation DB: Fix & finish compile_commands.json loading.
Compilation DB: Add cdb-menu item for non-CMake compile_commands.json.
Remove eproject, add missing licenses, create .dir-locals and add C++ modeline
Add support for .clang_complete.
Fix `irony-buffer-identifier' on emoty buffer-file-name.
A bit of documentation for .clang_complete.
Add a .clang_complete for irony-mode as an example.
Add support for include directories when using compilation DB.
Add colored diagnostics for Ninja + Clang builds.
Suggest to configure the project when a file has errors & various fixes.
Use file-truename for working-dir and delete-dups after path expansions
CDB: Add info tooltip for disabled item and change prompt.