Support Raspberry PI (ARMv6)
Undo attempt at supporting "long" and "double" on ARM
Merge branch 'master' of github.com:pocl/pocl into raspberry-pi
Remove explicit mention of -march=armv6 from makefiles
Remove outdated comment
Simplify types.h handling

Remove architecture-specifc handling of types.h.
Use clang-provided macros to distinguish target features.
Simplify kernel library handling

Remove architecture-specific directories.
Enable Vecmathlib for all architectures.
Simplify logic that handles build flags. Move remaining logic into configure.ac.
Improve clz and popcount kernel functions (code taken from TCE architecture).
Improve vload_half and vload_store kernel functions (code taken from ARM architecture).
Correct error in auto-detecting type sizes

The previous mechanism didn't properly distinguish between different languages. (C and OpenCL C may have different sizes for "long".)
Rename include files to prevent naming conflicts

Use "pocl_" prefix to prevent conflicts.
Note: Using an underscore as prefix does not work; e.g. _types.h is a system header file.
Update Vecmathlib from upstream
Correct detecting whether OpenCL long is supported
Correct Vecmathlib support file dependencies

Build Vecmathlib support files in their subdirectory.
Output original value as well when convert_type tests fail
Handle white space in path name
Correct printf format specifiers for size_t arguments
Use %lld to output "long" values

pocl's printf isn't OpenCL-conformant yet. 32-bit architectures require using %lld for "long".
Avoid testing failing type conversions

Do you test converting floating point numbers that would result in negative unsigned quantities.
Correct detection of unsigned types
Set -march from OCL_KERNEL_TARGET again (functionality was lost during cleanup)
Do not implement kernel functions for half type

This doesn't work on most architectures, and is also not part of the OpenCL standard.