Issue #2033415 by tankerjoe, lostkangaroo, batigolix, sandipmkhairnar, m1n0: Fix up hook_help for picture module

Issue #2083733 by maartendeblock, JurgenR, Cyclodex, Pixelstyle, tankerjoe: Add reinstall instructions to INSTALL.txt

Issue #2084535 by mErilainen, tankerjoe, DanielFbrg: Fix file_copy documentation around the case when source and destination are the same

Issue #2085957 by tankerjoe: Document that BookController methods return render arrays, not strings.