Always use standard mbstowcs() and wcstombs() functions.

Don't provide our own (not fully functional) definitions of them and always
use the system versions as we don't support OS X 10.2 which was the last
platform where these functions didn't exist/work.

See #15580.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@75024 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775
Remove our own dlxxx() functions emulation for OS X <= 10.3.

We don't support so old versions of OS X any more anyhow, so simplify the code
by using dlopen() &c directly instead of using our own wx_dlopen() with custom
implementation for OS X.

See #15580.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@75025 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775
No changes, just remove hard TABs from wxWebViewWebKit code.

This will allow to commit other changes to this file without triggering svn
hook checking for the TABs absence.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@75026 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775
Fix wrong UMAGetSystemVersion() return value comparison in wxScreenDC.

The return value of gestaltSystemVersion() represents the version as
"four hexadecimal digits in the low-order word of the return value", to quote
Apple documentation, not as a floating point number.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@75027 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775
Get rid of compile- and run-time checks for OS X < 10.5.

As 10.5 is the minimal supported version, it doesn't make sense to check for
it (or even earlier versions) during the build or run-time.

Closes #15580.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@75028 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775