Makefile: update DIRS to fix cleaning

Commits 40624100 and 72f2942df didn't update the variable accordingly.
mpvcore/path: Fix config path handling on Windows

Previously, mpv incorrectly used the %HOME% environment variable on
MinGW to determine the current user’s home directory. This is wrong;
the correct variable to use would be %HOMEPATH%, which would however
still be wrong since application data goes into the application data
directory, not the user’s home. This patch makes it use the local
AppData path instead of reading an environment variable.

This however exposed another problem (which also affected users who
actually had the %HOME% variable set):
b2c2fe7a3782 (discussed in issue #95) introduced some changes that
make mpv load user config files from the executable path on Windows.
The problem with this change is that config_dir was still declared
static, so once a config file had been found in the executable path,
it would set config_dir to an empty string, so mpv would dump e.g.
watch_later data straight into the user’s home. This commit also
fixes that.

One side effect of this is that mpv no longer considers the “mpv”
subdirectory in the executable path (that behavior resulted from
the homedir variable always being empty), unless it is somehow
unable to determine the local AppData path.
mpvcore/path: Fix non-MinGW builds

Well that was dumb.
macosx_application: fix file opening on OS X 10.9 (hopefully)

File opening through Finder, apparently drops `--psn` arguments on Mavericks
and just uses no args. Modify the code to account for that case.

This wasn't tested on 10.9 itself (I don't have a paid dev account), but it
*should* work if I understood the problem correctly.
macosx: always active bundle path lookup if cocoa is active

This is not really something you want to disable anyway. If there is no bundle
the code already does it's falbacks anyway.
macosx_application: fix file opening on 10.9 (for real this time)

I did commit 86c05655d by thinking `mpv` already removed the `mpv` from
argc/argv. It actually is still there, so the argc must be 1 to check for no
arguments.

Thanks to @Nyx0uf for pointing out the bug and for testing on 10.9!
vd_lavc: reset last_sample_aspect_ratio in uninit_avctx()

In init_vo(), if sh->aspect is 0 or last_sample_aspect_ratio is set,
sh->aspect is overwritten. With software decoding fallback behaviour,
this makes the aspect ratio from container ignored since
last_sample_aspect_ratio is already set in first try with hardware
decoding.
Release 0.1.6