[ originally reported by Olly Betts on #debian-devel ]

Ctags indexing is currently non-qualified, so indexing on OO langauges will not
contain class names, namespaces, etc.

To fix this we should add --extra=+q to ctags invocation. About this, the ctags
documentation says: "However, that this could potentially more than double the
size of the tag file".

Micro benchmarks:
- computation time is ~10-15% slower with +q
- size
  - libreoffice (C++)
    zack@tytso:~/ctags-bench/libreoffice-4.1.5$ wc ../libreoffice*ctags
    561396   3872260  61123731 ../libreoffice-4.1.5.ctags
    972942   6799455 117133590 ../libreoffice-4.1.5.extra+q.ctags
  - chromium-browser (C/C++)
    zack@tytso:~/ctags-bench/chromium-browser-32.0.1700.123$ wc ../chromium-browser*ctags
    1618199  10931585 205005488 ../chromium-browser-32.0.1700.123.ctags
    2472627  17064351 342772532 ../chromium-browser-32.0.1700.123.extra+q.ctags
  - linux (C)
    zack@tytso:~/ctags-bench/linux-3.12.9$ wc ../linux*ctags
    2146431  14340875 208057034 ../linux-3.12.9.ctags
    2610525  17780208 269391932 ../linux-3.12.9.extra+q.ctags

Bottom line: it's doable.  (But will need to rerun all ctags indexing after
having changed the ctags plugin code.)