use shared_ptr a little more thoroughly
Revert "use shared_ptr a little more thoroughly"

Farhod says it's too slow and it broke tests.
This reverts commit 4539a0ea96014a12dedf3648dc403af52158e513.
fixed changing main ledger page
Fixed ARMORY-260, armory connects to bitcoind too many times
Changed ARMORY-260 so that the cached connection to bitcoind is kept around even when offline. This connection is used elsewhere in the code and must be reference-able