Fixed a wrong type-alias for OFintegral_constant.

The type-alias defined when C++11 support was enabled did not honor the
special nature of std::integral_constant which takes a non-type argument
as its second template parameter.
Introduced C++11-like alignment support.

Created configure tests that detect the availability of various native
alignment specifiers on different platform / compiler combinations.
Implemented fallback definitions for OFalignas and OFalignof based on these
specifiers and the non-standard macros "OFalign" and "OFalign_typename"
which compensate for the reduced functionality available on Microsoft
compilers by employing C++ templates.
OFalign and OFalign_typename are also available on compilers supplying true
alignment support, making them the most platform-independent
implementations.
Fixed an alignment problem in OFoptional.

OFoptional now uses a policy based approach to manage its storage,
implemented as OFoptional_traits. This allows to customize memory
allocation and state management, as well as the default construction
policy.
The default implementation now uses OFalign when available, to align the
storage appropriately for its content type. If OFalign is not supported,
OFoptional falls back to an implementation employing pointers and
allocating the memory on the heap.
Fixed building 32 bit targets with mingw-w64.

Added configure-time tests for some file access functions that aren't
available on every MinGW distribution.
Minor fixes to file's comment header.
Updated copyright date and other minor changes.
Implemented copy constructors and added clone().

Implemented missing copy constructors for tree node classes and added clone()
methods to the relevant classes. This is the first step towards a better
support of SR templates, e.g. by preparing subtrees in advance that can later
be inserted into a document tree.
Added explaining comment on new copy constructor.
Removed outdated CMake exclude pattern.

Removed outdated "CVS" exclude pattern from CMake install command. After the
change from CVS to git there is no need to exclude the subdirectory anymore.
Excluded "*.md5" files from installation.

Excluded "*.md5" files generated by Doxygen (when "HAVE_DOT" is set to "YES")
from installation. This setting is e.g. used by Debian's DCMTK package.
Made sure that all top-level nodes are deleted.

Made sure that all nodes in the tree are deleted with clear(), even if there
is more than one node on the top-level (i.e. no dedicated root). This feature
will be needed for handling the upcoming document subtree class properly.
Added method counting the number of nodes.

Added method that counts the number of nodes stored in a tree.
Added two new convenience functions.

Added new convenience functions that allow for adding a new node (either on
the same level or as a child node) and for specifying the concept name with a
single call. Also added a test case for these functions and gotoNamedNode().
Fixed issue with tests run in different order.

Fixed issue with tests being run in different order when using the CMake
build system. Now, the ID of the next node to be created can be determined in
advance.
Add connection timeout setting to SCU class.

Add DCMTK's global connection timeout to SCU API. Though the timeout is still
a global settings, this enhances visibility to users. Enhanced documentation
comments about other existing timeout settings.
Fixed various Doxygen-related issues.

Fixed various Doxygen-related issues, mainly missing class name for some
identifiers. Also fixed wrong header include (where appropriate).
Introduced new class DSRDocumentSubTree.

Introduced new class DSRDocumentSubTree as the base class for the existing
class DSRDocumentTree. A subtree represents an extract of a SR document tree.
This new class is another step towards the future support of SR Templates.