Remove the use of go-spew.
Changed TxIn.PreviousOutpoint to TxIn.PreviousOutPoint after btcwire API change.
comment:script.go: ScriptDB->KeyDB
Fixed SignTxOutput doc spelling error.
Made hashType typed as SigHashType.
Convert all StackErrX to ErrStackX.

This commit changes all stack errors from the form of StackErrX to
ErrStackX which is the expected form for standard Go code.
Comment ScriptInfo struct according to standards.

Found by golint.
use btcec structs instead of ecdsa structs
Removed unnecessary signTxOutputCustomReader.
IMPORT PATH MODIFICATION CHANGESET
----------------------------------

Please use this changeset as the first one on top of the conformal codebase.
Note that if there are new imports, they need to be changed as part of this
changeset. In general, use "git rebase" on github.com/conformal's version
and apply this changeset first.