Allow whitespace in installers - fix for issue #2071

Custom installers can have the class definition indented.
Also try a php copy-and-remove on unix if mv failed, refs #1765
Init command - diacritical marks in author name
Make it clear what is going on when a vcs folder is missing, fixes #2108
Merge pull request #2114 from kibao/init-command-utf8-author-name

Init command - diacritical marks in author name
Merge pull request #2101 from e1en0r/patch-1

Allow whitespace in installers - fix for issue #2071
Retry file download also on Internal Server Error 500 code as is mostly a temporary glitch (at least on GitHub)
Attempt to fix travis build
Fix detection of git bitbucket repos with incorrect URLs, fixes #2095
Merge pull request #2118 from acasademont/retry_on_error

Retry file download also on Internal Server Error 500 code ...
Fix parsing of inferred stability flags that are more stable than the min stability
Fix typo, fixes #2126
Add debugging info for invalid zip files to try and get to the bottom of it, refs #2125
Fixed minor typo in composer.json example
Merge pull request #2131 from javiereguiluz/patch-1

Fixed minor typo in composer.json example
Fix test
Add ChangeReport Interface

Added a ChangeReport Interface to allow also non VCS-Downloaders to check the status of there package
CGL fix
Fixed getLocalChanges calls in VCS downloaders to match new function interface
Retry downloading when a corrupt zip is found, fixes #2133, fixes #2128, fixes #2125