Allow 'page' parameter to be configurable.

Refactor and testing of @meowcakes's #407.

Signed-off-by: Ben Corlett <bencorlett@me.com>
Fixed missing hard-coded reference to 'page' as the param.

Signed-off-by: Ben Corlett <bencorlett@me.com>
Adding tests for custom page parameter within the pagination environment context.

Signed-off-by: Ben Corlett <bencorlett@me.com>
Merge branch 'refs/heads/master' into feature/paginator-configurable-param
Merge branch 'master' into feature/paginator-configurable-param

Signed-off-by: Ben Corlett <bencorlett@me.com>

Conflicts:
	src/Illuminate/Pagination/Environment.php
Merge pull request #421 from bencorlett/feature/paginator-configurable-param

Allow 'page' parameter to be configurable.