recipes: add removal date to PNBLACKLIST messages

* based on discussion in pndeprecated thread:
  https://patchwork.openembedded.org/patch/137573/
  update the messages to warn possible users that the
  recipe will be removed before the end of the next development
  cycle (before Yocto 2.4 is released).

* updated with:
  sed -i 's/^\(PNBLACKLIST.*".*\)"/\1 - the recipe will be removed on 2017-09-01 unless the issue is fixed"/g' `git grep PNBLACKLIST | sed 's/:.*//g' | sort -u | xargs`
* then noticed couple recipes being blacklisted only based on
  DISTRO_FEATURES, so removed those:
  meta-networking/recipes-support/lksctp-tools/lksctp-tools_1.0.17.bb
  meta-oe/recipes-connectivity/bluez/bluez-hcidump_2.5.bb
  meta-oe/recipes-connectivity/bluez/bluez4_4.101.bb
  meta-oe/recipes-connectivity/bluez/gst-plugin-bluetooth_4.101.bb
  meta-oe/recipes-navigation/foxtrotgps/foxtrotgps_1.1.1.bb
  meta-oe/recipes-navigation/gypsy/gypsy.inc
  meta-oe/recipes-navigation/navit/navit.inc
  meta-oe/recipes-support/opensync/libsyncml_0.5.4.bb

* if it isn't fixed by this date, it's fair game to be removed
  whenever someone gets around to i

Signed-off-by: Martin Jansa <Martin.Jansa@gmail.com>

meta-gpe/recipes-support/fbreader/fbreader_0.12.10.bb

@@ -43,4 +43,4 @@ do_install() {
 SRC_URI[md5sum] = "da9ec4721efdb0ec0aaa182bff16ad82"
 SRC_URI[sha256sum] = "328aec454db80e225aa0b5c31adef74bf62a14357482947e87e9731686b3c624"
 
-PNBLACKLIST[fbreader] ?= "Depends on blacklisted libgpewidget"
+PNBLACKLIST[fbreader] ?= "Depends on blacklisted libgpewidget - the recipe will be removed on 2017-09-01 unless the issue is fixed"

meta-gpe/recipes-support/fbreader/fbreader_git.bb

@@ -42,4 +42,4 @@ do_install() {
 }
 
 # http://errors.yoctoproject.org/Errors/Details/68618/
-PNBLACKLIST[fbreader] ?= "BROKEN: fails to build with gcc-6"
+PNBLACKLIST[fbreader] ?= "BROKEN: fails to build with gcc-6 - the recipe will be removed on 2017-09-01 unless the issue is fixed"