UNO commands may optionally rotate or mirror their icons depending on context (usually based on writing direction). This approach is an easy way to provide large numbers of such context-sensitive icons, but suffers from serious drawbacks in certain cases. For example, icons which contain asymmetrical symbols or text will be obviously mirrored, and icon themes which use shading will appear inconsistent next to non-transformed icons from the same theme. This code change lets icon themes provide specialized graphics for the left-right-top-bottom text direction. Such specializations are available for any command which specifies COMMAND_PROPERTY_MIRROR. Direction-specialized versions should be placed in the `cmd/rltb` directory within the icon theme. Localized specializations may also be nested inside that directory. For example, icons in `cmd/rltb/en` will be used for English in RTL context. Change-Id: Ic7a8cf3a6657a171e92123413d1c47e621f1bddd Reviewed-on: https://gerrit.libreoffice.org/c/core/+/182761 Reviewed-by: Jonathan Clark <jonathan@libreoffice.org> Tested-by: Jenkins