Fix wrong debug symbols in shared ccache and more

New features:

• Add utils/stats script that prints stats for the last make

Fixes:

• Use gdbinit also when attaching gdb
• VSCode: settings for sphinx extension (not usable right now)
• Fix wrong debug symbols in shared ccache

Improvements:

• Manually load gdb pretty printers for libstdcxx

Internal changes:

• Update script for analyzing ninja logs
• Use ccache's logstats functionality
• Tweak distcc instructions