Merge branch 'jc/test-lazy-prereq' (early part)

* 'jc/test-lazy-prereq' (early part):
  t3419: drop unnecessary NOT_EXPENSIVE pseudo-prerequisite
  t3302: drop unnecessary NOT_EXPENSIVE pseudo-prerequisite
  t3302: do not chdir around in the primary test process
  t3302: coding style updates
  test: turn USR_BIN_TIME into a lazy prerequisite
  test: turn EXPENSIVE into a lazy prerequisite

diff --cc t/t5551-http-fetch-smart.sh
Simple merge

diff --cc t/test-lib.sh
Simple merge