[JBIDE-18956] Freemarker New and Noteworthy for 4.2.1.Final

Fix includes N&N page for freemarker
add JB 4.2.1 and fix URLs for 4.2.0.CR1
JBT 4.2.1.Final and JBDS 8.0.1 release blog
release 801GA
Fixed broken image in OpenShift N&N for JBT 4.2.1.Final
Fixing title in Freemarker N&N
Archiving pre-releases of JBT 4.2.0 and DevStudio 8.0.0
Restoring a fix to avoid failures at rebuild (dev mode)
Rewording the blog announcement for DevStudio 8.0.1.GA