Import Boost 1.55.0b1.

This is a beta version with Visual Studio 2013 support.
Use modified smallbuild of Berkeley DB.

This is a smaller configuration that removes some unneeded stuff.  We
can't use the standard smallbuild configuration, because Poedit's TM
uses the hash method, but other than that, disable the advanced stuff
(e.g. replication, which is quite heavy).
Add a CLI tool for dumping TM content.

Copy the bits of transmem.cpp relevant for reading into a new file.
Remove uses of wxWidgets, replacing them with std::string etc. Modernize
the code a little bit. Add enumeration of all keys and write simple CLI
interface for dumping everything to stdout in a primitive XML format.
Remove USE_TRANSMEM, build unconditionally.

Don't make the TM optional, build it unconditionally.  Linux distros
presumably enabled it anyway (and libdb is standard there) and both OS X
and Windows versions always shipped it.  No point in complicated the
code with all these #ifdefs.
Merge branch 'vendor/boost' into new-translation-memory

Update Boost to version compatible with Visual Studio 2013. This becomes
relevant, because some libs needed by Lucene++ couldn't be compiled with it in
1.54.1.
Boost compilation fix for VS2013.

See:
https://svn.boost.org/trac/boost/ticket/9249
https://svn.boost.org/trac/boost/changeset/84443
Add LucenePlusPlus submodule.

Also include Xcode and Visual Studio projects for it.  Add projects for
dependencies (more Boost libraries, zlib on Windows).
Open the legacy DB as read-only.
Remove TM update wizard.

The UI was unintuitive and confusing.  Will be replaced with proper
import from files option later on.
Completely rewrite the translation memory using Lucene.

The ancient homegrown algorithm from the old TM left a lot to be
desired.  Use Lucene's search to provide better results even in the
current somewhat naive implementation - even so, it is a much better
basis for further improvements.
Add an import button for feeding the TM with files.
Change TransactionMemory API to use batch updates.

Writing translations individually and committing right away is painfully
slow.  Use transactional API exclusively.
VS build: Don't use expat & zlib from wx.

They are used directly elsewhere, so build wx using our copy.
Add code for migrating from Berkeley to Lucene TM formats.
Merge branch 'new-translation-memory'
Fix syntax error introduced in 80f6e3b.