* fix: Relates to #466. Refer to Fether FAQ for instructions

* fix: Reword error messages to start with the Webcam word so its easier for users to troubleshoot using Fether FAQ

* feat: Add ExternalLink component to direct the user to the FAQ. Colour it blue

* review-fix: Modify webcam troubleshooting link text

See https://electronjs.org/docs/api/frameless-window#draggable-region

* Move toggle details buttons and associated methods and showDetails state into nav of TxForm component

* Pass showDetails down as props to TxDetails

* Remove previous attempt to display TxDetails like a popup above other fields
(i.e. remove form-details-wrapper and -details-value styles)

* Note: To quickly see the changes force the Onboarding component (displaying Terms & Conditions screen) to appear by changing
`if (isFirstRun) {` to `if (true) {` in `fether-react/src/App/App.js. The screen should be consistent when you run `yarn taskbar` and `yarn start`

* Add eggshell background colour to `body` element  otherwise `yarn taskbar` app has grey background (even though
running as normal `yarn start` or `yarn electron` app has white background from manifest)

* Note: To quickly see the changes force the Onboarding component (displaying Terms & Conditions screen) to appear by changing
`if (isFirstRun) {` to `if (true) {` in `fether-react/src/App/App.js. The screen should be consistent when you run `yarn taskbar` and `yarn start`

* Terms & Conditions updates for consistency and compatibility with taskbar app

	* Add extra side padding `-padded-extra` to Terms & Conditions so consistent with rest of site and in taskbar app

	* Wrap with `.terms-and-conditions-wrapper` to add box shadow around both the
	'Please read carefully' label and associated Terms & Conditions

	* Adjust height of `.terms-and-conditions` down to 16rem otherwise with more side padding it causes
	overflow to occur with vertical scrollbar appearing (checked that it works on both taskbar app
	i.e. `yarn taskbar` and normal app `yarn electron` or `yarn start`)

	* Hide `overflow-x` in Terms and Conditions as caused horizontal scroll on taskbar app

	* Add top margin to Terms and Conditions so extra gap from its 'Please read carefully' label

	* Only left padding in Terms and Conditions

* Move "Details" / "Hide" buttons into the form-nav footer section

* TxDetails now appears above the footer area above other input fields without causing the screen height to increase

* Background of the TxDetails darkened so it stands out from surroudings

* Change "Details" arrow to point upwards since TxDetails now shown above

* Change "Hide" arrow to point downward since TxDetails now shown above

* Rename classnames to `_` or `-` more consistently

* Note: To quickly display the 'Details' button so you can click it change TxForm.js as follows:

```
{/* {valid && this.estimatedTxFee(values) ? ( */}
  <TxDetails
    // estimatedTxFee={this.estimatedTxFee(values)}
    estimatedTxFee={new BigNumber('8100000')}
    token={token}
    // values={values}
    values={ { amount: new BigNumber('0.1'), gasPrice: new BigNumber('21000') } }
  />
{/* ) : null} */}

review-fix: Hide vertical overflow on body element so scrollbar not flicker on/off when TxDetails toggled

* Create TxDetails component and move relevant instance methods from TxForm into TxDetails

* Fix linting warning `Using target="_blank" without rel="noopener noreferrer" is a security risk: see https://mathiasbynens.github.io/rel-noopener`

* After entering a valid value and a recipient address, it works but the console displays error: `Uncaught TypeError: Cannot read property 'resolve' of null at flush (index.js:62)`

* On the 'Send THIBCoin' if you enter a valid value and a recipient address, the Tx Fee Estimate is shown as being the same value as the Amount, which is incorrect!