Add Ledger support for Musicoin

EIP-155 is now properly working with Musicoin!! Tested personally on the Ledger Nano S

    homepage           : https://musicoin.org
    block explorer     : https://explorer.musicoin.org
    slip0044 index     : 184
    chainId            : 7762959

Musicoin has been unable to work with hardware wallets until the following changes were applied:
LedgerHQ/app-ethereum@8260268
LedgerHQ/app-ethereum@74c085c

The Musicoin network has had EIP-155 Replay attack protection enabled on their network ever since the following PR got merged in February:
Musicoin/go-musicoin#62

Musicoin is on LedgerHQ official roadmap:
https://trello.com/c/a3YFOxx1/114-musicoin-support

LedgerHQ official Musicoin app support: (merged)
LedgerHQ/app-ethereum#20

app/scripts/directives/walletDecryptDrtv.html

@@ -35,7 +35,7 @@ <h4 translate="decrypt_Access">
     <!-- Ledger -->
     <label aria-flowto="aria3"
            class="radio"
-           ng-show="ajaxReq.type=='ETH'||ajaxReq.type=='ETC'||ajaxReq.type=='ROPSTEN ETH'||ajaxReq.type=='RINKEBY ETH'||ajaxReq.type=='KOVAN ETH'||ajaxReq.type=='EXP'||ajaxReq.type=='UBQ'||ajaxReq.type=='POA'||ajaxReq.type=='TOMO'||ajaxReq.type=='ESN'||ajaxReq.type=='AKROMA'||ajaxReq.type=='PIRL'||ajaxReq.type=='ETHO'||ajaxReq.type=='EGEM'||ajaxReq.type=='CLO'||ajaxReq.type=='ATH'">
+           ng-show="ajaxReq.type=='ETH'||ajaxReq.type=='ETC'||ajaxReq.type=='ROPSTEN ETH'||ajaxReq.type=='RINKEBY ETH'||ajaxReq.type=='KOVAN ETH'||ajaxReq.type=='EXP'||ajaxReq.type=='UBQ'||ajaxReq.type=='POA'||ajaxReq.type=='TOMO'||ajaxReq.type=='ESN'||ajaxReq.type=='AKROMA'||ajaxReq.type=='PIRL'||ajaxReq.type=='ETHO'||ajaxReq.type=='EGEM'||ajaxReq.type=='CLO'||ajaxReq.type=='ATH'||ajaxReq.type=='MUSIC'">
       <input aria-flowto="aria3"
              type="radio"
              aria-label="Ledger Hardware Wallet"