Addresses issue #1463. Replaces preg_replace '\e' modifier with preg_replace_callback as '\e' is depracated as of PHP 5.5.0.
Add emphasis on turning debug on prior to submitting an issue
README Update

* New CI image
* Releases links
Fix error if SERVER_SOFTWARE is not a defined key
Remove /e in preg_replace. Fixes #1463

This is just a quick fix. This will be replaced in 2.0 with function yourls_replace_string_tokens() from the Feature-Design branch
Add Travis translations test
Fix duplicated directory
Fix Travis script
String declaration
Clean travis command
Avoid checking an empty array when loading plugins
Leo doesn't like PHP 5.2 :^Þ
Be sure to have REQUEST_URI before trying redirection
Check REQUEST_URI before actually running tests on it.. duh.
Safer DB version number, and debug feedback if failure on install

Related:
- https://github.com/YOURLS/YOURLS/issues/1479#issuecomment-23428747
- https://core.trac.wordpress.org/ticket/25228
Make install function more nuclear to improves feedback & UT
Pass parameter to yourls_hash_passwords_now(). Will make tests easier.
Make yourls_hash_passwords_now() independent from globals

This will allow to unit test that function on an arbitrary file
Geo IP function fix, for IPv4 and IPv6. Fixes #1482
Make yourls_load_default_textdomain() return something.

Will just make UT easier.