docs: misc changes;
add path to adb tool in sdk;
fix broken link to ninepatch docs;
fix and add some other links
Change-Id: I27c7284ac2db2e6020c9cb0115fb932a2f503033
I haven't touched instances of "behaviour", "dequeue", "removeable",
"resizeable", or "removeable" because all are accepted variant spellings
and I don't know what the policy is on such things.
