Merge remote-tracking branch 'simensen/non-dev-version'

Conflicts:
	src/Composer/Package/Loader/RootPackageLoader.php
	tests/Composer/Test/Package/Loader/RootPackageLoaderTest.php
Fix detection of tags when the current tag is not a valid version
Skip best adapter since it can create issues on some platforms, fixes #2168
Fix whatProvides returning too many results when no constraint is given
Describe tag names more consistently, fixes #2170
Adjust cache-dir docs, fixes #1667
Abort quickly if the only match is class= in a file
Fix a typo.
Merge pull request #2175 from Hywan/typo

Fix a typo
Merge pull request #2153 from renanbr/archive-prefer-dist

prefer-dist and archive synchronized
Correctly set watch2 on rule watch nodes for learned rules fixes #2181
Improve reporting of github rate limiting errors, fixes #2183
Fix output of invalid zip files when download is retried
Fix display of commands in ProcessExecutor, refs #2146
Add global command to be able to require/install/update global packages, fixes #1813, fixes #55
Add docs for global command
Merge branch 'global'
Allow the authentications to be loaded in the IO independently
Mark class as abstract
Fix typo