Update and add images for 4_4_6 changes to managing_data.txt and web_client.txt
Updates to text of managing_data.txt for 4_4_6 changes
Update text of web_client.txt for changes in 4_4_6
Add image manageAttach.jpg
Make small fixes on developers' testing page.

Main problem was the OmeroPy path which was simply wrong.
Use canned styles following sbesson's suggestions.

also cleaned up some whitespace
Fix test class links, per sbesson's suggestion.
getting-started.txt
Updated image name reference
Corrected line spacing for indented lines
Added bold
managing_data.txt add - and
import_data.txt - updated text for last point
Removing images/tutor/webClientBatch.jpg
added webclientBatch.jpg
Modify managingName.jpg to show channel edit pen icon
Ressurect the ArrayColumn documentation

This reverts commit 48f3a5c3bb4b1b25e1306c93a50b30a68388c39b.
Added doc for FloatArrayColumn
Add clarification that Float/Double/Long are 32/64/64 bits
Remove long from values type since it applies to multiple column types
fixed width -> fixed-width
Merge pull request #278 from gusferguson/rebased/develop/training_updates_4_4_6

Training updates 4 4 6 (rebased onto develop)
Make further changes suggested by Helen.