all: starting development of 2.6.0
lib: internal: cacheimpl: processIndexFile: tiny speed-up: avoid explicit eof() calls
lib: internal: cacheimpl: processTranslationFile: tiny optimization: there is no need for shared_ptr to store translation file objects
lib: internal: worker: packages: __create_virtual_actions: removed the comment part which is obsolete after 7411ec763899c89f93ad667ac4b551edfab4625b
lib: cached: added TODO: remove Cache::PinnedVersion constructor
lib: internal: worker: packages: __create_virtual_edge: tiny optimization: use existing installed versions
Merge tag '2.5.3' into next

2.5.3 release

Conflicts:
	debian/changelog
lib: bumped the API version
downloadmethods: fixed API bumping -related code places
lib: cache: package and version pointers are now persistent and bound to Cache object
lib: cached: PinnedVersion: commit 'ca95cd78' also removes constructor
lib: cache: relation: ArchitecturedRelationExpression: constructor from string subrange is now explicit
lib: cache: relation: ArchitecturedRelation: constructor from string subrange is now explicit
lib: pipe: removed from the public interface
lib: internal: worker: packages: markAsAutomaticallyInstalled: don't use deprecated Cache::getPathOfExtendedStates()
lib: internal: worker: snapshots: don't use deprecated Cache methods
lib: cache: removed deprecated methods
debian: changelog: 2.6.0: typo fix: s/Architecutured/Architectured
lib: internal: pipe: removed unneeded header unistd.h
debian: changelog: removed the paragraph about 'pipe: removed'

Cupt::Pipe was a non-documented interface.