version.py: Also update the version in the plugin documentation
version.py: Also update the version in the plugin documentation

Refactor the code so that the replacement is done in a submethod
using `re.sub` on the entire content of the file, rather than per
line.

Use the refactored method to also do the replacement in the VERSION
file.

Add replacement in the dev-plugin file in the Documentation.

Change-Id: I5ca81e5c290ba4635a92b56b1680e906429b11c8

hdost/gerrit,Seinlin/gerrit,WANdisco/gerrit,gerrit-review/gerrit,thesamet/gerrit,Seinlin/gerrit,MerritCR/merrit,joshuawilson/merrit,hdost/gerrit,netroby/gerrit,MerritCR/merrit,netroby/gerrit,thesamet/gerrit,quyixia/gerrit,qtproject/qtqa-gerrit,netroby/gerrit,netroby/gerrit,hdost/gerrit,renchaorevee/gerrit,TonyChai24/test,gerrit-review/gerrit,hdost/gerrit,supriyantomaftuh/gerrit,pkdevbox/gerrit,joshuawilson/merrit,WANdisco/gerrit,quyixia/gerrit,jackminicloud/test,Seinlin/gerrit,supriyantomaftuh/gerrit,gerrit-review/gerrit,MerritCR/merrit,Seinlin/gerrit,TonyChai24/test,MerritCR/merrit,qtproject/qtqa-gerrit,supriyantomaftuh/gerrit,MerritCR/merrit,TonyChai24/test,GerritCodeReview/gerrit,renchaorevee/gerrit,GerritCodeReview/gerrit,gerrit-review/gerrit,supriyantomaftuh/gerrit,jackminicloud/test,qtproject/qtqa-gerrit,quyixia/gerrit,netroby/gerrit,thesamet/gerrit,quyixia/gerrit,renchaorevee/gerrit,WANdisco/gerrit,GerritCodeReview/gerrit,MerritCR/merrit,quyixia/gerrit,joshuawilson/merrit,joshuawilson/merrit,hdost/gerrit,WANdisco/gerrit,quyixia/gerrit,TonyChai24/test,hdost/gerrit,jackminicloud/test,Seinlin/gerrit,renchaorevee/gerrit,MerritCR/merrit,thesamet/gerrit,qtproject/qtqa-gerrit,quyixia/gerrit,thesamet/gerrit,GerritCodeReview/gerrit,pkdevbox/gerrit,joshuawilson/merrit,TonyChai24/test,GerritCodeReview/gerrit,WANdisco/gerrit,Seinlin/gerrit,supriyantomaftuh/gerrit,supriyantomaftuh/gerrit,WANdisco/gerrit,gerrit-review/gerrit,pkdevbox/gerrit,GerritCodeReview/gerrit,pkdevbox/gerrit,jackminicloud/test,qtproject/qtqa-gerrit,jackminicloud/test,netroby/gerrit,renchaorevee/gerrit,hdost/gerrit,renchaorevee/gerrit,thesamet/gerrit,joshuawilson/merrit,TonyChai24/test,joshuawilson/merrit,jackminicloud/test,pkdevbox/gerrit,GerritCodeReview/gerrit,qtproject/qtqa-gerrit,qtproject/qtqa-gerrit,gerrit-review/gerrit,joshuawilson/merrit,TonyChai24/test,thesamet/gerrit,renchaorevee/gerrit,Seinlin/gerrit,pkdevbox/gerrit,jackminicloud/test,gerrit-review/gerrit,WANdisco/gerrit,supriyantomaftuh/gerrit,pkdevbox/gerrit,netroby/gerrit,MerritCR/merrit,GerritCodeReview/gerrit