configure: Do not use pthread_create to check for pthread

Certain instrumentation addons leads to a false positive in configure
and link failures at the end of the build phase.

Signed-off-by: Luca Barbato <lu_zero@gentoo.org>
dcadec: Add some logging before returning on error

Based on a patch by Michael Niedermayer.

Signed-off-by: Luca Barbato <lu_zero@gentoo.org>
gitignore: Ignore multilibrary example programs
doc: Try to find nonstandard Perl path from the environment
dsputil: x86: Move ff_inv_zigzag_direct16 table init to mpegvideo

The table is MMX-specific and used nowhere else.
build: Add shorthand for HOSTCC compile macro
build: Add rule for building host-specific object files
dv: Move DV VLC data tables out of header file
dv: Split off DV video encoder into its own file