Improved build instructions for fresh clone of repository
fixed run_websocket way of running websocket app
Fix proper error reporting
Adding documentation on how to build submodules
Added pyzmq as the dependency
Save tile size with changed name
Don't provide a default value for image dimensions

All Images in the database now have a 'dimensions' field. If a new Image
without a sensible 'dimensions' field is saved, a validation exception
should rightfully be raised. Providing a nonsense "[0,0,0]" default value
is not a good thing, as it may disguise bugs where 'dimensions' isn't
being set.
Merge branch 'image_dimension'

* image_dimension:
  Don't provide a default value for image dimensions
Fix Python style issues in glviewer

* all indents should use 4 spaces per level
* statements should not terminate with a semicolon
Remove commented stack PDB debugging statements
Clean some trailing whitespace
Merge branch 'misc_style'

* misc_style:
  Clean some trailing whitespace
  Remove commented stack PDB debugging statements
  Fix Python style issues in glviewer
Remove 'Image.extents' field

This field is superseded by 'dimensions'. All Image documents in the
database have been updated to remove the 'extents' field, after ensuring
that 'dimensions' contained equivalent data.
Merge branch 'image_extents'

* image_extents:
  Remove 'Image.extents' field
Fix for loading ptif files with correct tile_size
Return 404 if tile not found
Merge branch 'fix/ptif-tilesizee'

* fix/ptif-tilesizee:
  Return 404 if tile not found
  Fix for loading ptif files with correct tile_size
Remove Celery from requirements

Celery is not actively used yet.

Also fix some whitespace
Upgrade Flask-Admin to bump minor version
Merge branch 'requirements'

* requirements:
  Upgrade Flask-Admin to bump minor version
  Remove Celery from requirements