LRDOCS-995 Add check-images ant target and taskdef for Dev Site
LRDOCS-995 Add copy CheckImagesTask class to edit
LRDOCS-995 Edit new CheckImagesTaskDevSite class to handle new dev site dir structure
LRDOCS-995 Image DNE; changed to existing duplicate image, for now
LRDOCS-995 Check-images task should use dir structure, not exact name
LRDOCS-995 Also index for forward slash, since not all OS's use backslashes for paths
Merge branch 'check-images-2' of https://github.com/codyhoag/liferay-docs into dev-site