Signed-off-by: Alessandro-Barbieri <lssndrbarbieri@gmail.com>

Using --without-arg was not being respected

* NANOX_CONFIGURE_ARGS was being defined in several lines breaking
    the configure step.
* Remove or replace obsolete macros

Also, remove unused and refactor some variables

Program checks can cause problems when cross-compiling

* Remove DLB library versioning, only link agaist ldlb
* Remove DLB dependency on support lib
* Add DLB dependency on pms lib

Some ARM extensions (such NEON) require saving additional registers in the context switch. This commit fixes the problem with ARM architecture that requires disabling the user level threads (--disable-ut) to avoid problems with prints

Fix #1231

Fix #1227

Installed devinclude headers have conditional code depending on options
detected at configure time. This header is needed in the prefix to match
those ones to the installed libraries.

Do not abort the configure if the OpenCL installation is present
but broken and the user did not explicitly asked for it.

Do not disable opencl if Altera's OpenCL is not present.

This reverts commit ff81a05b, reversing
changes made to 60a04672.

The invalidation_improvements branch needs more testing on its own,
after merging some applications stopped to work correctly, so
there is something wrong in that branch.
The subsequent commits are also reverted, except the one bumping
the version to 0.12a.

For whatever reason, [ 6 -ge 6.0 ] is false

Adding task callback experimental mechanism; enabled through configure option --enable-task-callback; closes #1156

MPI architecture is now correctly appended to ARCHITECTURES
variable. Otherwise, offload support will not be enabled even if
MPI was checked successfully.

Added Intel MPI multithread library flag -link_mpi, since the
former -mt_mpi is now deprecated.

Added missing 'unset' directives that were preventing the checks
for MPI compiler to be skipped due to autoconf cached values.

Closes #1155