message: only show change power level option in MemberInfo if we can actually
  send m.room.power_level AND are lower PL than them
diff: @@ -545,7 +545,7 @@ module.exports = withMatrixClient(React.createClass({
  can.ban = me.powerLevel >= powerLevels.ban;
  can.mute = me.powerLevel >= editPowerLevel;
  can.toggleMod = me.powerLevel > them.powerLevel && them.powerLevel >= levelToSend;
  - can.modifyLevel = me.powerLevel > them.powerLevel;
  + can.modifyLevel = me.powerLevel > them.powerLevel && me.powerLevel >= editPowerLevel;
  return can;
  },
  @@ -814,7 +814,9 @@ module.exports = withMatrixClient(React.createClass({
  { this.props.member.userId }
  </div>
  <div className="mx_MemberInfo_profileField">
  - { _t("Level:") } <b><PowerSelector controlled={true} value={parseInt(this.props.member.powerLevel)} disabled={!this.state.can.modifyLevel} onChange={this.onPowerChange} /></b>
  + { _t("Level:") } <b>
  + <PowerSelector controlled={true} value={parseInt(this.props.member.powerLevel)} disabled={!this.state.can.modifyLevel} onChange={this.onPowerChange} />
  + </b>
  </div>
  <div className="mx_MemberInfo_profileField">
  <PresenceLabel activeAgo={presenceLastActiveAgo}
  