search: Self-documenting atoms

Parse errors in the atoms have a position too
Easier to add new search predicates

Change-Id: I9d2e890b9afcfb524aafa8f1e4e1debc683555ac
Merge "search: Self-documenting atoms"
jsonconfig: Int64 support

Change-Id: I933e5f86d0f5a55402ab9218fba8ffbfee8efa26
Start of 'proxycache' blobserver type.

Change-Id: I8702c1d02203090899eee6c0a555f6fc1dba4e7e