Change version number in file/directory names

Step 2 of version bump

Minor: Fix incorrect version number in a doc-comment

Bump version number to 4.9

Minor: Remove redundant autoloading mechanism

Merge pull request YahnisElsts#320 from DaveMoran/update-readme-links

Update links to readme.txt documentation

Another attempt to fix the Composer autoloader

Attempt to fix errors caused by using Composer-generated autoloaders …

…when multiple versions of the library are loaded at the same time.

See YahnisElsts#300. Apparently, when using the `files` autoloading mechanism, Composer will only include the files for one version of the library (i.e. the first one loaded). Let's see if we can fix that by switching to a `psr-0` autoloader. This requires a bunch of changes to the standalone autoloader and the factory registration process.

Changed version number to 4.7

Bump version number to 4.6

Update the docs to more clearly separate usage instructions for GitLa…

…b.com and self-hosted GitLab instances.