mobile: initial wrappers for mobile support

.travis.yml

accounts/abi/bind/bind.go

accounts/abi/bind/bind_test.go

accounts/abi/bind/template.go

accounts/key_store_passphrase.go

cmd/abigen/main.go

cmd/utils/bootnodes.go

cmd/utils/flags.go

common/types.go

core/types/block.go

mobile/accounts.go

mobile/big.go

mobile/big_go1.7.go

mobile/bind.go

mobile/common.go

mobile/context.go

mobile/core.go

mobile/discover.go

mobile/doc.go

mobile/ethclient.go