NoWriteSecurityManager options ("-writeableDirPrefixes nnn:nnn:nnn").
NoWriteSecurityManager tweaks for mkdir().
Merge branch 'master' of github.com:OpenEndedGroup/Field

# Please enter a commit message to explain why this merge is necessary,
# especially if it merges an updated upstream into a topic branch.
#
# Lines starting with '#' will be ignored, and an empty message aborts
# the commit.
Merge.
Merge branch 'master' of github.com:OpenEndedGroup/Field

# Please enter a commit message to explain why this merge is necessary,
# especially if it merges an updated upstream into a topic branch.
#
# Lines starting with '#' will be ignored, and an empty message aborts
# the commit.
isTransient() error is transient.
Merge pull request #38 from cassiel/master

-writeableDirPrefixes xxx:xxx:xxx.