Add vim modeline to try to force sensible code formatting in the future.
Started tidying up cpp_interface. An interface header file shouldn't really
have the implementations in it!
Remove "using ..." from cpp_interface header file. These declarations
SHOULD NEVER BE IN A PUBLIC HEADER FILE because this may cause conflicts
with what the client is using.
Clean up CPP interface a little more by forward declaring STPMgr and
UserDefinedFlags so that we don't need to include them.
Changed LETMgr object to a unique_ptr so we can forward declare it
and avoid including its header file in cpp_interface.h
Fix memory leak in C interface
Update c_interface.cpp
Merge pull request #108 from sneves/master

Fix memory leak in C interface
Making 'Var' into uint32_t and removing typedef

Typedef is ambigous: cryptominisat2 also has this typedef and it's
pretty useless, too. Also, it shouldn't be an int, but an unsigned int
Merge pull request #110 from msoos/var_fixed

Making 'Var' into uint32_t and removing typedef
Added CMake option ENABLE_ASSERTIONS which is enabled for default.
This will cause any build configuration (that we support) to be
built with assertions.

Internally this implemented by removing any ``-DDEBUG`` flags
from the CMAKE_CXX_FLAGS_<CONFIGURATION> and
CMAKE_C_FLAGS_<CONFIGURATION> cache variables. The ``-DDEBUG`` is
then manually added or removed using add_defintions() (note this
does not add the flags to cache variables).
Merge pull request #112 from delcypher/enable_assertions_option

Added CMake option ENABLE_ASSERTIONS which is enabled for default.
Fixing typo in gnu+11 compiler flag

Thanks to zlqhem for indicating this

Fixes #102
Less broken define-fun declare-fun
Allow to use CryptoMiniSat4 as an option
Adding files to allow for cryptominisat4 to be used
Don't fall back silently to CMS2, print to stderr before
Fixing type in BBNodeManagerAIG.h

Thanks for @jamesjer for pointing this out

Fixes #117
Fix detection of CryptoMinisat4. A FindCryptoMiniSat4 CMake module
is not needed because cryptominisat4 exports its targets that can
be picked up by using find_package() in config mode.

If the CryptoMiniSat4 cannot be found the user will see a message
like this...

```
CMake Warning at CMakeLists.txt:224 (find_package):
  Could not find a package configuration file provided by "cryptominisat4"
  with any of the following names:

    cryptominisat4Config.cmake
    cryptominisat4-config.cmake

  Add the installation prefix of "cryptominisat4" to CMAKE_PREFIX_PATH or set
  "cryptominisat4_DIR" to a directory containing one of the above files.  If
  "cryptominisat4" provides a separate development package or SDK, be sure it
  has been installed.
```

The user can fix this by setting the cryptominisat4_DIR option
(e.g. cmake -Dcryptominisat4_DIR:STRING=/path/to/cryptominisat4/build).

This should be set the directory containing the ``cryptominisat4Config.cmake``
which is available in CryptoMinisat4's build directory and also on a system
with CryptoMinisat4 installed (usually <prefix>/lib/cmake/cryptominisat4/)
Extra test files, some for recent parsing changes.