configure: Use enable_weak when enabling pic

This allows it to be overridden, either by the user on the command
line, or by other sections of the configure script.

Signed-off-by: Martin Storsjö <martin@martin.st>
configure: Explicitly disable PIC when targeting win32/mingw

These platforms do not have any notion of PIC. On some compilers,
enabling pic produces a number of warnings.

This avoids trying to produce PIC loads in the ARM assembly - there
are no relocation types in PE/COFF that correspond to
BFD_RELOC_32_PCREL (R_ARM_REL32 in ELF).

As a side-effect, this avoids enabling PIC on mingw64, getting rid
of the warnings about PIC not having any effect on that platform.

Signed-off-by: Martin Storsjö <martin@martin.st>
configure: Rename cmov processor capability to i686

The goal is to make the capapility slightly more general and have it
cover the availability of the nopl instruction in addition to cmov.
configure: x86: Only enable cpunop on i686

The assembler may insert nopl instructions for cpunop, which are not
(universally) supported on i586 CPUs.
x86: dsputil: Refactor pixels16 wrapper functions with a macro
x86: dsputil: Split inline assembly from init code

Also remove some pointless comments.
x86: dsputil: Rename dsputil_mmx.h --> dsputil_x86.h

The header is not (anymore) MMX-specific.
configure: Disable PIC for cygwin just as for win32/mingw

If this is explicitly disabled for win32/mingw, it should also
be disabled for cygwin, for consistency and for the same reasons
as for win32/mingw.

Signed-off-by: Martin Storsjö <martin@martin.st>
dynamic loading of shared faac library
no Werror on implicit-function-declaration and missing-prototypes
custom icon and windows resource
use upstream version tag, my repo is always rebased