fix GC mistake in 3892e13
maybe relevant to #3476
pkg2: use dir=pkg for more git commands instead changing directory.
pkg2 wip: stub of the update function.
fix another GC mistake. should fix #3476
fix perf regression in 5f65f568e6e6de92b3d514eec76d14971c9326a7
add type checking for named argument containers
allow passing empty keyword arg container to functions that don't accept
keyword args
Fix #3482 - typo in socket.jl
added rsplit. fixed rsearch for a case when both string and pattern are empty.
incorporated comments and corrections