Performance optimisations and removal of cache dir

The following changes since commit 2670ddf4482f61e83aefb9cc061fc4d3a5d615b5:

  Also add Stephen Rothwell (2013-01-21 17:31:30 +0000)

are available in the git repository at:

  https://github.com/mikey/undistract-me master

for you to fetch changes up to f7df0af235da29defefef784cf25ed0a671b1166:

  Change env var names to avoid global naming conflicts (2013-02-11 11:36:13 +1100)

----------------------------------------------------------------
Michael Neuling (3):
      preexec: optimise performance by turning the DEBUG trap on and off
      Use env vars rather than the cache dir
      Change env var names to avoid global naming conflicts

 long-running.bash |   96 +++++++++++++++--------------------------------------
 preexec.bash      |   20 ++---------
 2 files changed, 29 insertions(+), 87 deletions(-)