Bed Dimensions in Printer Settings
remove unused Variables
Merge branch 'devel' into Salandora-settings
Settings for bed dimension (PR) and extruder offsets

Changed the bed dimension PR slightly to use a computed property instead of two separate values and only a computed reader, added options for extruder offsets.
Extracted all used regexes in the comm layer and precompiled them

Possible improvement of #390

(cherry picked from commit 89cae22b9130865a75d1e8eee15c7924b1a89402)

Conflicts:
	src/octoprint/util/comm.py
Renamed compiled regexes to match the new naming scheme
Fixed temperature graph again after changes from last night
Hopefully fixed a race condition that could occur when pressing "Print" (file not opened yet, but comm layer tries to fetch next command)
Changed handling of bed temperatures

Will now be left unset if not detected (instead of dying a horrible death), modified frontend to not display bed settings in such cases. While at it also (hopefully) fixed "Target: off" for bed issue.

TODO: Support repetier's "TargetBed:", "TargetExtr%n" syntax

Fixes #399, partially solves #360
Also support repetier target temperature output

 Should fix #360
Added post roll to timelapse

You can now define an amount of seconds that should be added to the rendered timelapse (so, since the current fps setting is 25 frames per seconds, 25 * the configured amount of post roll seconds images will need to be captured).

Timed timelapses add this to the actual run time of the timelapse capturing process (so if you configure 1s post roll, a timed timelapse will run 25s longer than the print)

Z-triggered timelapses just create one last capture from the webcam and use this image again and again (so 25 times for a post roll of 1s).

Implements #384
Fix for saved timelapse configs vs. new post roll setting

See #384
Do not try to send bed temp on API if not available
Virtual printer now supports "repetier style" target temperature reporting
Fixed a regex matcher
Fixed M110 and sd status reporting on virtual printer
Added configurable timeout settings for temperature and sd status query, made communication timeout reset everytime a non-empty line is received from the printer
Do not overwrite possibly existing target temp if only a single hotend is present

See #360
Operate on current transformation matrix when zooming

Closes #398
Merge pull request #2 from foosel/devel

Pulling foosel Devel