feat(webapps/front-end-build): introduce auto-build task

This commit adds the auto-build task to the front-end build.

grunt auto-build -> automatically rebuilds sources on change, live
reloads app if opened

grunt build -> executes single run of dev build
grunt build:dist -> executed single run of dist build (including
minification and so forth)

More documentation on the tasks can be found in the updated README.md.

Related to CAM-1712
test(engine/receive): task without message and parallel correlation

related to #CAM-1612
fix(container/jmx): do not treat folders in process scanning

fixes #CAM-1787
docs(cockpit): add/improve some jsdoc comment

Closes CAM-1727
Merge branch 'master' of github.com:camunda/camunda-bpm-platform
improve(cockpit): show dots to indicate a shortend id

related to CAM-996
chore(engine): adjust namespace of HistoricStatistics MyBatis mapping
chore(cockpit/css): add new class to position a badge on diagram

related to CAM-1579
fix(webapps/front-end-build): use vendor bootstrap styles

Related to CAM-1712
feat(webapps/front-end-build): optimize build

Get rid of a number of resources in final build

- use locally packaged bootstrap
- use locally packaged angular-ui
- renamed assets/patched to assets/local for clarity
- add .patched or -patched to patched resources for clarity
- update require-conf to reflect new changes

Related to CAM-1712
chore(webapps/front-end-build): remove unused bower libs
 chore(release): Prepare release: set version to 7.1.0-alpha2
 chore(release): Prepare next development version: 7.1.0-SNAPSHOT
feat(webapp/test/util): provide a new camunda webapp test utility

This commit adds a new module called "camunda-webapp-test-utility" that
provides a "JobExecutorHelper" and a "DbSchemaPrefixTestHelper". Those can
be used inside custom plugins to write test cases which uses a JobExecutor
or to run the unit test against a db table prefix.

related to CAM-1798
chore(maven): use correct maven config tag
chore(maven): add ejb-client to central profile, bom inherits from parent
improve(grunt): rewording "production" into "dist"
feat(cockpit/candidate groups): add the ability to manage groups of a task

This commit adds a button in the user task table
who opens a modal window allowing to add or remove candidate groups to a user task.
For easier testing of that new feature a process definition called "User task identity links test 1"
with predefined groups, assignee and owners has been created.

Additional changes:
- A small directive providing a widget to edit, simple text variable, in place - like the name of asignee
- Adds some comments for jsdoc
- Improve the linting of some files

Closes CAM-1182
chore(qa): add postgresql 9.3 support

related to CAM-1592
fix(qa): add postgresql 9.3 support

related to CAM-1592