code cleanup

* some CodePro Analytix findings
refactoring: make better use of sql query cache
Refactoring: remove double initialization
Refactoring: use explicit size to get better performance
Refactoring: do not build a string within a StringBuilder append()
Refactoring: remove redundant variable
Refactoring: remove redundant else
Refactoring: remove unnecessary "this" qualifiers
Refactoring: use local variable instead of field
refactoring: 3 tests fail if cache type is not ALL
fix #2235: use a more lax regexp to identify found caches
Merge branch 'release' into upstream
fix: remove undesired space between trackable log entries

* caused by bad parsing
* every entry had additional <div> tags
Change log update release

#2235
#2208
#2247
#2253
Polish typo fix and shorter string

As suggested by a user (have to trust him)
Merge pull request #2264 from Lineflyer/release

Change log update release + Polish string correction
Merge branch 'release'

Conflicts:
	main/res/values/strings.xml
Change log finetuning

Removed "New Feature" section for next maintenance release as there are none.
fix #2259: premium caches not identified in searches
Merge branch 'release' into upstream

Conflicts:
	main/res/values/strings.xml