[Build System] Add test for C++11 initializer list
[FieldVector] Change FieldVector default constructor to default-initialize data

The default constructor of the FieldVector has intentionally avoided calling a
constructor for the contained data to eliminate the potential overhead of that
initialization.
During implementation of a new creation mode of the BCRSMatrix, it was discovered
that this behavior is problematic due to its inconsistency: If the data type
contained in the FieldVector is a non-trivial type, a default-constructed
FieldVector will be fully initialized. On the other hand, with a primitive data
type it will be in an uninitialized state, potentially causing undefined behavior.

As this behavior might be very unintuitive for users and made implementing the new,
more efficient creation method for the BCRS matrix very difficult to implement, this
patch changes the FieldVector default constructor to always default-construct its
contents regardless of its type. While this change does introduce a possible
performance regression (for primitive types, the compiler now has to zero out the
memory), the overhead has been measured to be minimal.

The actual implementation prefers to use the new C++11 unified initialization
syntax and falls back to std::fill for older compilers. The distinction was made
because newer compilers generate much more efficient code when using unified
initialization, and for user-defined types, this approach avoids first calling the
default constructors and then the copy assignment operator.
Fixes documentation of interface that facaded objects have to provide.
[Parallel][Bugfix] Always initialize variable.

Previously, a variable (found) was only initialized in one branch
of an if statement but used later on in any case. This patch makes
sure that is initialized in both branches.
[CMake] Look for folders "test", not "test*".

Before this commit it matched e.g. "test1" and failed finding the directory "test".
[CMake] Make CPack usable from all dune modules.
[cleanup] Move methods hasPrefix, hasSuffix into a separate file stringutility.hh
[cleanup] Move class Factorial from misc.hh to math.hh
[cleanup] mark method SQR as deprecated
[cleanup] Move complex conjugation et al to math.hh
Deprecate the header misc.hh
[cleanup] Don't include misc.hh, it is not used
[cleanup] Include stringutility.hh instead of misc.hh
[bugfix] add missing headers
Merge branch 'master' of http://git.dune-project.org/repositories/dune-common
Merge branch 'master' into feature/FS1322-initialize-fieldvector
Include math.hh to have conjugateComplex
Merge branch 'feature/FS1322-initialize-fieldvector'
[c++11] add support for C++11 constexpr

As decided on the developer meeting in Aachen, we support (but do not
rely on) the C++11 keyword constexpr. This patch adds an m4-check for
constexpr and a header (cxx11.hh) defining a macro DUNE_CONSTEXPR either
as constexpr or empty (depending on the compiler support for it). It is
then used in FieldVector and FieldMatrix on size, rows, and cols.
[CMake][Bugfix] Fix search for test directories.

The patch from ...fce82c7d5ee5 broke the script.
This is the intended behavior.