[Typetraits][Compatibility] Provide partial backwards compatibility for is_indexable on old GCC versions

Older GCC versions have some nasty bugs related to SFINAE and indexing
with operator[]. This patch adds a configuration check for those
problems and a partial backwards compatibility hack for those older
compilers that is sufficient for our current use case in the VTK
writer.

is_indexable can be used to test whether a type can be indexed (via
operator[]).

Maybe we can deprecate the complete header type_traits.hh.

Use conditional instead.

Because C++11 implements this differently, and we now have an
stl-compliant implementation to switch to.

I would deprecate isPointer and isReference too, but I can't find
a way to do it.

These are replacements for TypeTraits::isPointer, TypeTraits::isReference,
TypeTraits::PointeeType.  They reimplement what is available in the
C++11 standard library, and are expected to supersede the TypeTraits
class eventually.

Note: this patch does not pull in the corresponding stl implementation.

If not found, our own fallback implementation will be used.

The C++11 standard library offers the functionality of SelectType,
it is, however, called 'conditional'.  This patch adds a copy
of our SelectType implementation with the class names changed
to match the ones used in C++11.  The old SelectType implementation
gets deprecated.

C++11 requires a cast operator from integral_constant< T, v > to T. As far as I
could make out, no gcc version provides this cast in <tr1/type_traits> and only
gcc >= 4.6 provides it in <type_traits>. Therefore, the configure check now tests
for the cast operator only in <type_traits>.

Note: Our drop-in replacement conforms to the standard in the above-mentioned
sense.

[[Imported from SVN: r6992]]

types.

[[Imported from SVN: r6078]]

If there is an implementation available in std or std::tr1 we fall back to
that.

[[Imported from SVN: r6022]]

[[Imported from SVN: r5804]]

[[Imported from SVN: r5789]]

[[Imported from SVN: r5742]]

[[Imported from SVN: r5741]]

[[Imported from SVN: r5666]]

* update Makefiles and configure

[[Imported from SVN: r5643]]

[[Imported from SVN: r5555]]

[[Imported from SVN: r5551]]

fixes a problem with gcc-4.3, where <tr1/typetraits> and <typetraits> are present:
/usr/people/nolte/numerics/dune/dune-common/dune/common/typetraits.hh:274: error: ‘std::enable_if’ has not been declared

[[Imported from SVN: r5453]]

add enable_if as an stl-conforming replacement of EnableIf.  Take it from the library header if present.  Deprecate EnableIf

[[Imported from SVN: r5396]]

[[Imported from SVN: r5321]]

the classes RemoveConst and SameType, which have been deprecated in 1.1, are now removed.  Use remove_const and is_same instead

[[Imported from SVN: r5133]]

[[Imported from SVN: r5032]]

[[Imported from SVN: r5031]]

[[Imported from SVN: r5005]]

[[Imported from SVN: r4963]]

Put the classes SameType and RemoveConst back in for backward compatibility.  Marking them as deprecated doesn't work, due to gcc bug 16370

[[Imported from SVN: r4888]]

[[Imported from SVN: r4857]]

[[Imported from SVN: r4848]]

[[Imported from SVN: r4847]]

RemoveConst (except that the return type is now 'type' instead of 'Type').
If the tr1/type_traits header is present, remove_const will be taken from
there.  If not, remove_const is a copy of the RemoveConst class in this
file.

[[Imported from SVN: r4844]]