ImGui_GM v1.0.11

hi! v1.0.11 brings a few internal changes to allow for the extension to be used in older versions of gamemaker (namely LTS). there's also a fix for the "__Initialize not set before reading" issue that appeared on new releases of GM

Fixes:

• Addressed the "ImGui not set before reading" error that would popup when using ImGui_GM in some newer versions of GM

Changes:

• You can now use ImGui_GM in versions of GameMaker without "static_get"
  • ImGui_GM will check for the existence of this function upon launch, if not found; a one-time warning will be displayed explaining how to setup ImGui_GM for use in your version of GameMaker
  • After renaming the ImGui class to "ImGui_", the class will be constructed and stored in a globalvar named "ImGui" (essentially mimicking the already mimicked namespacing ImGui_GM uses)