increase rate at which tox_do() is called

file transfers need tox_do() to be called often to reach high speeds
fix multiple file transfers

FileTransfer .filenumber was not being set
fixed file transfers for multiple friends

file transfer ids are per friend, not global
added resuming file transfers

-only works with disconnects (and not client restarts)
only set file transfer to broken if it was in progress
sending file data without reading/writing to file

-automatically accepts .png files <=1MiB as data
sending clipboard as png
displaying received png in chat

-missing option to "Save As" the images
accept and display jpg images too

-send clipboard as jpg if png of clipboard >1MiB
-images aligned to left in chat now
show progress when recieving data
Merge branch 'working' of github.com:notsecure/Venom into notsecure-working
Merge branch 'notsecure-working'
reworked settings dialog, replaced apply/cancel buttons with a close button, insta-applying settings via property binding now
Https for freenode, fix the download link
Merge branch 'stqism-patch-2'
ui design reworked to look more similar to new mockup
- Added smiley.svg for smiley button
- Added smiley button (currently nonfunctional)
- (Re)added border radius for various widgets
- Added "DEBUG" define if CMAKE_BUILD_TYPE is debug
- (Re)added F5 theme refresh if build type is debug
- Added filetransfer.svg for filetransfer button (currently hidden)
- Updated Cellrenderer to get correct color for selected rows
- Removed Arrow button, moved all functionality to status button (for
  now)
- Made button_send_file visible on groupchats
small cellrenderer fix, using Gtk.CellRendererState flags instead of doing it the hard way
bugfix for userbutton on older gtk versions