Contextclasses implement XFastContextHandler
Importclasses implement XFastDocumentHandler
Tokens for BlockList.xml are defined in BlockListTokens.txt
Tokens for content.xml are defined in TextBlockTokens.txt
A perfect hash table is generated with gperf and used by the tokenhandlers

This is corrected version of c1e90457
(Also pushing again follow-up c940d4d3
"loplugin:saloverride" and 5f0f3d4e
"Work around -Werror,-Wdeprecated-register")
The commits were reverted in 7ef4457b

Change-Id: I08cd852fa751f98fd0ac6a55dda22f82a869b4d8