Revert "Improved support for including rulesets inside other rulesets using relative paths"

This reverts commit bc8c394b381bc407df8feb8c83e500f75cb4d6a5. Code is being rewritten in 1.5.0 and this change may cause backwards compatibility issues for some rare cases.
Fixed bug #19871 : findExtendedClassName doesn't return FQCN on namespaced classes
Fixed bug #19879 : bitwise and operator interpreted as reference by value
Squiz BlockCommentSniff no longer reports that a blank line between a scope closer and block comment is invalid
Merge branch 'master' into report-memory-improvements

Conflicts:
	CodeSniffer.php