WebUI: Don't empty transfer list before updating it

This causes the list from disappearing in IE 10.
No longer needed table rows are deleted anyway.
Merge pull request #2150 from pmzqla/webui-fix

WebUI: Don't empty transfer list before updating it
WebUI: make API locale independet

Sizes are now given in bytes.
Dates are Unix timestamps and converted to ISO 8601 in the web UI.
Numbers are not converted to strings.
-1 is returned for undefined values.

Some keys have been splitted:

Torrent list (json/torrents)
 * num_seeds: Torrent seeds connected to
 * num_complete: Torrent seeds in the swarm
 * num_leechs: Torrent leechers connected to
 * num_incomplete: Torrent leechers in the swarm

Torrent generic properties (propertiesGeneral/hash)
 * total_uploaded: Total data uploaded
 * total_uploaded_session: Total data uploaded this session
 * total_downloaded: Total data dowloaded
 * total_downloaded_session: Total data downloaded this session
 * time_elapsed: Torrent elapsed time
 * seeding_time: Torrent elapsed time while complete
 * nb_connections: Torrent connection count
 * nb_connections_limit: Torrent connection count limit

Global transfer info (json/transferInfo)
 * dl_info_speed: Global downalod rate
 * dl_info_data: Data downloaded this session
 * up_info_speed: Global upload rate
 * up_info_data: Data uploaded this session

Closes #1524.
Remove unneeded parameters from helper functions for WebUI
Use raw data to sort columns

Store the raw data retrieved in a new data-raw attribute and use
these to sort the columns.

In addition, make the ETA column sortable.
Use localeCompare to sort torrent list by name
Merge pull request #2145 from pmzqla/webui

Make Web API locale independent
Implement episode filter for rss downloader
Add tooltip to episode filter text edit
Fix configure script when running with dash

`test 1 == 1` will fail using dash as the default shell. The `test 1 = 1`
syntax works in both Bash and Dash.
Merge pull request #2156 from jleclanche/master

Fix configure script when running with dash
Reduce the number of torrent_handle::torrent_file() calls in QTorrentHandle::prioritize_files(). Closes #2161.

It was reported (#2161) that enabling/disabling a downloading of a file
is considerably slow on libtorrent 1.0.3, but not on 0.16.x. The problem
is that a function torrent_file() in libttorrent 1.0.3 does a deep copy
of torrent_info, while get_torrent_info() in libtorrent 0.16.x only
returns a reference.
Merge pull request #2163 from sorokin/optimize-prioritize-files

Reduce the number of torrent_handle::torrent_file() calls in QTorrentHandle::prioritize_files()
Merge pull request #800 from Gelmir/smart_ep

Implement episode filter for rss downloader
Documenting the project's coding guidelines. Closes #2091.