Change help messages to use new hierarchical commands

refs #264580
Merge pull request #283 from Icenium/totev/fix-messgaes

Change help messages to use new hierarchical commands
Make sure init and sample commands don't fail in rare cases
Merge pull request #284 from Icenium/tashkov/fix-init

Make sure init and sample commands don't fail in rare cases
fix missing waits on httpRequest()

#265283
Merge pull request #286 from Icenium/dragnev/fix-httprequest

fix missing wait() on httpRequest() resulting in fiber-related crashes
Fix using of old command names and in help