Update error_messages; capitalize first character

Result of a discussion: https://groups.google.com/forum/#!topic/web2py/IDkr4w_wKv4
The intent is to convert the first character of all error messages to a capital letter.
Allow empty reference field in form without IS_EMPTY_OR() validator, avoiding constraint violation exception
fix bug related to upgrade setuptools / pip
Merge pull request #351 from kirsn/master

Update error_messages; capitalize first character
Merge pull request #352 from viniciusban/empty_reference_field

Allow empty reference field in form without IS_EMPTY_OR() validator, avoiding constraint violation exception.
Merge pull request #353 from ilvalle/create_view

codemirror 3.21
Merge pull request #354 from alfonsodg/master

fix bug related to upgrade setuptools / pip
fixed issue 1839: catch exception if source code cannot be opened in the debugger
updated simple soap contrib (pysimplesoap version 1.11)
added soap examples app (used in tests)
fixed issue 153: correct 500 status if there is a SOAP fault
added soap client/server test (including for status 500 to check issue #153)
fixed WebClient contrib to properly send raw data in POST methods
Merge pull request #355 from reingart/master

debugger and soap contrib update and fixes
someone forgot tests.... grrrr!
Merge pull request #356 from niphlod/fix/tests

someone forgot tests.... grrrr!
online editor: shortcuts in a separated frame and style review