Added support for SQLCipher database driver in KMyMoney

Database backend supports SQLCipher driver. Added a new method to
KMyMoney's SQL driver which stores information if a password is
supported.

Also a new QSQLDriver for SQLCipher was introduced.

This is still work in progress as some features are missing (e.g.
encrypt not encrypted database and vice versa, change password). But
install is hard so only sophisticated users and engaged package
maintainer can do that. I do not think this will be useful in near
future. However I wanted to shared my code.

How to install/use this patch:

1) You need SQLCipher, http://sqlcipher.net , build and install it (to
my knowledge it is not packed in any major distribution).

2) Get the qt source code (or just the one for QSQLiteDriver) and
build it (needed as this will create the necessary folder hierarchy).

3) If you do not install to default location, enable CMake to find
these folders (SQLCipher install folders, Qt source folder, Qt build folder).

4) Create KMyMoney with ENABLE_SQLCIPHER=ON (default is off)

Forgot: I have no clue how secure SQLCipher is! Just wanted to see if I
can get it running.

REVIEW: 116819