readme: clarify options, esp. regarding security.

See also: expressjs/csurf#12
docs: fix secure documentation

closes #43
Fix parsing logic around resave option

closes #44
deps: update test dependencies
1.2.1
deps: debug@1.0.2
deps: update testing dependencies
build: fix name in comment
build: use compact formats in package
docs: move badges
docs: move maintainer note
build: test coverage with istanbul
Integrate with express "trust proxy" by default

closes #48
1.3.0
build: add description in package
1.3.1
deps: buffer-crc32@0.2.3
tests: add a couple more tests
tests: add basic test for rolling option
Add option to control saving uninitialized sessions to storage

closes #8
closes #45