Issue #2853183 by quietone, darvanen, slootjes, Munavijayalakshmi, himanshu-dixit, shubham.prakash, gaurav.kapoor, prash_98, alexpott, JohnAlbin: Correct references from Symfony Framework

Issue #3138746 by jungle, rajandro, sja112, longwave, jameszhang023, quietone, dww: Fix 45 "shouldBeCamelCased" and related typos in core

Issue #2075889 by pwolanin, kgoel, alexpott, catch, mpdonadio, YesCT, himanshu-dixit, dawehner, xjm, johnshortess, Crell, jhodgdon, Wim Leers, mradcliffe, attiks, tstoeckler, webchick: Make Drupal handle incoming paths in a case-insensitive fashion for routing

Issue #2075889 by kgoel, pwolanin, catch, YesCT, dawehner, mpdonadio, johnshortess, Crell, mradcliffe, alexpott, webchick, ohthehugemanatee: Document that Drupal will handle incoming paths in a consistent and case-insensitive fashion for routing

Issue #2547707 by kekkis, screon, deepakaryan1988, latikas, jhodgdon, hussainweb, teemuaro, Crell, HeimdallJHM: Split routing documentation out of menu.api.php