Add Ability to mask passwords in the UI and in saved Events

[jankatins]

We don't want passwords saved to any disk/DB or shown in any UI so we need the ability to mask them. This masks passwords in the log (before it's actually shown/written) and in the node pages. I'm not sure if there are more places.

[jankatins]

This is how to get data from the local secret store on a mac so that passwords are not written in local_setup.py:

def getpassword(service, account):
    import re
    import os
    def decode_hex(s):
        s = eval('"' + re.sub(r"(..)", r"\x\1", s) + '"')
        if "" in s: s = s[:s.index("")]
        return s

    cmd = ' '.join([
        "/usr/bin/security",
        " find-generic-password",
        "-g -s '%s' -a '%s'" % (service, account),
        "2>&1 >/dev/null"
    ])
    p = os.popen(cmd)
    s = p.read()
    p.close()
    m = re.match(r"password: (?:0x([0-9A-F]+)\s*)?\"(.*)\"$", s)
    if m:
        hexform, stringform = m.groups()
        if hexform:
            return decode_hex(hexform)
        else:
            return stringform

def setpassword(service, account):
    import os
    import getpass
    password = getpass.getpass()
    cmd = 'security add-generic-password -U -a %s -s %s -p \'%s\'' % (account, service, password)
    p = os.popen(cmd)
    s = p.read()
    p.close()

# set with setpassword("mara","whatever")
whatever_password = getpassword("mara", "whatever")