Message/API rename: createAccount, createAssetAccount ->
registerAccount.

Those commands were used to produce the changes in this commit:

find . | egrep "(cpp|hpp)$" | xargs sed -r -i -e 's/create(Asset)?Account/registerAccount/g'
find . | egrep "(cpp|hpp)$" | xargs sed -i -e 's/CreateAccount/RegisterAccount/g'
Rename SERVER_ID -> NOTARY_ID.

find . | egrep "(cpp|hpp)$" | xargs sed -i -e 's/serverID/notaryID/g'
Rename "asset type" by "instrument definition" (in comments).
find . | egrep "(cpp|hpp)$" | xargs sed -i -e 's/asset type/instrument definition/g
Rename asset_type_id -> instrument_definition_id.

find . | egrep "(cpp|hpp|proto)$" | xargs sed -r -i -e 's/asset_(type_)?i[dD]/instrument_definition_id/g'
Rename CreateUserAccount -> RegisterNym.

Addendum to 570b31a.
Rename: userID -> nymID (all variants).

find . | egrep "(cpp|hpp|proto)$" | xargs sed -i -e 's/userI[dD]/nymID/g'
find . | egrep "(cpp|hpp|proto)$" | xargs sed -i -e 's/user_id/nym_id/g'
find . | egrep "(cpp|hpp|proto)$" | xargs sed -i -e 's/USER_ID/NYM_ID/g'
Rename message: deleteAssetAccount -> unregisterAccount.

Note: the API functions keep the "delete" because they delete the
account on the client side.

find . | egrep "(cpp|hpp|proto)$" | xargs sed -i -e 's/deleteAssetAccount/unregisterAccount/g'
find . | egrep "(cpp|hpp|proto)$" | xargs sed -i -e 's/DeleteAssetAccount/UnregisterAccount/g'
Rename assetAccount -> account.
Message/API rename: getNym_MarketOffers -> getNymMarketOffers,
getNym_MarketOffersResponse -> getNymMarketOffersResponse.

find . | egrep "(cpp|hpp|proto)$" | xargs sed -i -e 's/getNym_MarketOffers/getNymMarketOffers/g'
find . | egrep "(cpp|hpp|proto)$" | xargs sed -i -e 's/GetNym_MarketOffers/GetNymMarketOffers/g'
find . | egrep "(cpp|hpp|proto)$" | xargs sed -i -e 's/getNym_MarketOffersResponse/getNymMarketOffersResponse/g'
find . | egrep "(cpp|hpp|proto)$" | xargs sed -i -e 's/GetNym_MarketOffersResponse/GetNymMarketOffersResponse/g'