Correct the name of Doxyfile containing the version.

Use the correct file name in the version update script and version update
instructions, it is called just Doxyfile and not Doxyfile_inc now.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/branches/WX_3_0_BRANCH@75262 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775
Update version to 3.0.1.

And regenerate everything.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/branches/WX_3_0_BRANCH@75263 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775
Add symbols added in r75258 to version-script.in.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/branches/WX_3_0_BRANCH@75264 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775