Added additional assert() statements for OpenCL multi-context operations.
Replaced expression template handling for vectors: Full expression is set up.

Whenever one of {=,+=,-=} is encountered, the expression is then evaluated
by possibly splitting the expression into smaller tokens, introducing temporaries.
Implementation ready for vector. Further improvements necessary.
As it compiles and tests pass, this is an intermediate stable state.
Split op_prod into {op_mult, op_prod, op_element_mult}, similarly for op_div, rearranged op_executor, removed some temporaries.

The split of op_prod as well as op_div into {op_div, op_element_div}
allows to collect some more operations within a single overload for the expression executor.
Completely refurbished the generator
Fixed performance regression in ocl::checkError()

Spurious std::string objects were created from const char *, not optimized away by compiler.
Rewrote GEN-BLAS1 test to consistently test when the same operation is being re-enqueued with different arguments (without being regenerated)
Minor interface changes in the generator.

* Added source_code accessor for custom operation
* Renamed scalar_reduction_base into symbolic_scalar_reduction_base
Extended vector test suite for better coverage of operations without temporaries.
Added remaining overloads for vector operations in order to remove as many temporaries as possible.
Fixed warning and compilation error when using clang.

Warning was due to the use of 'typename' outside a template scope.
Error was due to a friend declaration of a static function.
Fixed a bug for the vector expression x -= y / alpha, where alpha is scalar<T>
Fixed a bug in element_div() introduced by splitting operator tags.

op_div was supplemented by op_element_div, for which the predicate
metafunction was not yet overloaded.
Finished full expression templates for matrices. All tests pass.

Follows the path used for vector expressions.
Some more exotic input combinations may not work yet.
Removed obsolete VECTOR_EXTRACTOR<> and MATRIX_EXTRACTOR<> classes.
Three-dimensional execution of OpenCL kernels now possible.
Fixed a warning related to an empty if-body.
Fixed a warning because of an unused variable in mixed-precision-CG.
Fixed operator overload problems on Visual Studio 2010 and 2012.
Normalization: Removed trailing whitespace in auxiliary/ folder, replaced tabs by spaces.
Removed trailing whitespaces in doc/