docs($http): remove duplicate 'to' in withCredentials description

Typo in $http config documentation

Closes #7731
chore(CHANGELOG.md): add changes for 1.2.17 and 1.3.0-beta-11
docs(tutorial): mention additional Debian install step

Thanks to GSC Leticia (gsc-leticia) for identifying this problem.

Closes #7665
perf(isArray): use native Array.isArray

see benchmark: http://jsperf.com/isarray-performance

Closes #7735
Merge pull request #6 from angular/master

chore(CHANGELOG.md): add changes for 1.2.17 and 1.3.0-beta-11