Updated core

Project: help  b726222b3b24c87972e772bb5f20e620784cfae5

helpcontent2: fix incremental rebuild of *.ilst files

They only depend on the perl script so won't get rebuild if images are
added or removed in source/media/

Use the same hack as in postprocess, make the targets PHONY so they
always get rebuilt.

Also fix a stray \ that caused the wrong output "[PRL] " to be printed
too early.

Change-Id: I03c8696591cf47395211feaed360fbd5642733a0

helpcontent2 @ b726222b

-Subproject commit ca78b4f149dd82723a3b53a93063c881096fa71f
+Subproject commit b726222b3b24c87972e772bb5f20e620784cfae5