Fix dailymotion "search" return bug message

Bug(dailymotion): Not enough elements found (1 expected) with selector "div.sd_video_previewtwig"

Signed-off-by: Vincent Texier <vit@free.fr>
bash completion: hide errors (closes #1671)

For system installation, the bash auto-completion will display messages
for users without home directory. Redirect stderr to null
Fix module francetelevisions "search" always return empty list

Signed-off-by: Vincent Texier <vit@free.fr>
Fix pyflakes (forgot to amend the previous commit)
Add argument for compatibility with python 2.6

Closes: #1651
weboobcfg: Format capabilities as JSON array

Capabilities was always displayed as a single list of entries
separated by comma. This is not really efficient as the reader has to
parse this string to retrieve atomic informations, even in JSON.

This patch allows to display the capabilities as an array, allowing
standard JSON parsers to immediatly returns a valuable information.
[biplan] site changed
[boobcoming] fix 1667 : boobcoming crashes with no end_date
introduce Loic Bontonou and Pierre-Louis Bonicoli
core: Log full backtrace on module build error