KICAD_MANAGER_FRAME Ctor. Two advantages:
- it is built after the splash screen is dismissed.
- if there are issues when creating the PLUGIN_CONTENT_MANAGER, this is more
easy to debug
Change teardrop generation to rely more heavily on BOARD_CONNECTIVITY
for improved performance.
Add updating of teardrops on BOARD_COMMIT::Push().
Also converts m_CopperItemRTreeCache to std::shared_ptr.
We don't copy it around anyway, and having to create a new set
of std::unique_ptr's for each operation is likely to be more
expensive than std::shared_ptr's overhead.
Jon Evans
jean-pierre charras
Jeff Young