UI: Dark theme padding and alignment fixes

Makes Visual C runtime libraries consistent across
Debug/MinSizeRel/Release/RelWithDebInfo, rather than just changing those
flags for RelWithDebInfo.  Also adds /Zl for statically linked
libraries.

Closes obsproject/obs-studio#1421

libobs: Export image-file to c

libobs: Add HLSL annotation parsing

Wraps image-file.h in extern "C" like rest of libobs api.

Prevents unresolved external errors when using in c++.

(This also modifies the CI scripts accordingly)

It was difficult to build local obs-browser builds on macOS due to the
way the frameworks work and libraries are linked.  This solves that
issue so that local builds of obs-browser should always work fine.

UI: Add ability to style preview background color

UI: Add Search to Hotkeys settings menu

cmake: Fix an error when SWIG isn't found

Fix README RST

This commit adds a filter bar to the top of the hotkeys settings menu,
with it set to look for matches anywhere in the string label for that
hotkey.

Change README hyperlinks from Markdown style to RST style. Make URLs
HTTPS. Correct some grammar.

obs-scripting CMakeList.txt expects SWIG, Python3 or Luajit to enable
scripting so in case of not finding just return and don't abort
the configuration

UI: Set about dialog as non-resizable

Add documentation for:

size_t gs_param_get_num_annotations(const gs_eparam_t *param)

gs_eparam_t *gs_param_get_annotation_by_idx(const gs_eparam_t *param,
		size_t annotation);

gs_eparam_t *gs_param_get_annotation_by_name(const gs_eparam_t *param,
		const char *name);

void *gs_effect_get_val(gs_eparam_t *param);

void *gs_effect_get_default_val(gs_eparam_t *param);

size_t gs_effect_get_val_size(gs_eparam_t *param);

size_t gs_effect_get_default_val_size(gs_eparam_t *param);

Adds api functions to extract gs_eparam_t values, including
gs_effect_get_val(), gs_effect_get_val_size(),
gs_effect_get_default_val() and gs_effect_get_default_val_size()

Gives the ability to retrieve param annotations. Blocks wrapped in <>
following a parameter.

For example:
float slider < float max_value = 10.0; float min_value = 0.0; >;

These blocks are not for shading purposes but to help describe the
shader's gui as in the example above.

Adds graphics api functions for retrieving annotations:
size_t gs_param_get_num_annotations(const gs_eparam_t *param);

gs_eparam_t *gs_param_get_annotation_by_idx(const gs_eparam_t *param,
		size_t annotation);

gs_eparam_t *gs_param_get_annotation_by_name(const gs_eparam_t *param,
		const char *name);

libobs/UI: Allow Access To argc/argv

UI: Implement stereo balancing

decklink: Add deactivate when not showing option to decklink

UI: Add about dialog

Shifting an integer larger than its bit width can have undefined
behavior.  This not only fixes that issue, but also optimizes the
shift functions.

Fixes the install_obs_data_file cmake helper function to be more
consistent across operating systems.

Adds a deactivate when not showing checkbox to decklink sources.

Cleanup Compilation warnings

Allows copying an individual file (which may not be in the data dir) to
an specified install location.

Variables path and dir with the same declared size triggers a compiler
warning about possible truncation. Although, depending on the path
where profiles are stored, its still possible to go beyong the declared
size and the path will be invalid. This will not trigger any
compilation warning and all invalid paths will be cought by the already
check in the os_glob function.

Some security layer libraries code path used by the rtmp output had a
not used variable and not used param on HMAC_finish macro that was
triggering warnings during compilation.

On 64bit systems, this check will always evaluate to false due to
SIZE_MAX type and triggers a compiler warning.

This both makes it clearer that its only needed on 32bit system and
clear the compiler warning.

[win-capture] Modify log for sharedmem

image-source: Add psd and *.* to file filter.