Build without playvid if no libavresample available

Allow the build to complete (without playvid and qplayvid) on pre-libav9
distros which do not provide libavresample.

Signed-off-by: Kamal Mostafa <kamal@whence.com>
Add install targets

... for everything except the python stuff.

Signed-off-by: Kamal Mostafa <kamal@whence.com>
olGetCharWidth() now takes a 'height' scalar arg

... same as the rest of font routines do.

Signed-off-by: Kamal Mostafa <kamal@whence.com>
Fix config.h.in typo HAVE_POSIX_MEMALIGN

Signed-off-by: Kamal Mostafa <kamal@whence.com>
Dynamic font types: olGetFont(), olFreeFont() framework

This framework allows for the implementation of different font types including
dynamically loaded fonts.  Fonts are allocated and loaded via e.g.:

	Font *font = olGetFont(OL_FONT_SOMETHING, "somefontname");

Only OL_FONT_DEFAULT is currently implemented, hence:
	olGetFont(OL_FONT_DEFAULT, "unused")
is equivalent to:
	olGetDefaultFont()

olFreeFont(font) should be called to free fonts returned by olGetFont(),
though freeing the default font is unnecessary (but harmless).

No functional change (until some future type is implemented).

Signed-off-by: Kamal Mostafa <kamal@whence.com>
olGetStringWidth() cleanup

No functional change.

Signed-off-by: Kamal Mostafa <kamal@whence.com>
olDrawChar() refactor

No functional change.

Signed-off-by: Kamal Mostafa <kamal@whence.com>
Hershey fonts support via libhersheyfont

If the libhersheyfont library is installed, build with support for
Hershey vector fonts.  Adds new olFontType OL_HERSHEY_FONT, e.g.:

    Font *olGetFont(OL_HERSHEY_FONT, fontname);
    ...
    olFreeFont(font);

Signed-off-by: Kamal Mostafa <kamal@whence.com>
spin-text: an OpenLase example app

Demo app for the font engine -- supports the 'default' font and Hershey fonts.

Signed-off-by: Kamal Mostafa <kamal@whence.com>