Improve the METAR handling

[István Váradi]

Currently METARs are displayed on the briefing pages. Sometimes they cannot be downloaded, and if the pilot is not attentive enough, he/she leaves the fields empty and then the PIREP will also miss the METARs.

It is proposed to add METAR fields to the takeoff and landing pages containing the respective METARs. The new fields should be editable and should be kept in sync with the fields on the briefing pages. One should not be able to go the next page unless the fields contain something.

[István Váradi <ivaradi@…>]

In d3f929e0eb3bd0519488b7760c17b44efd8271c5:

If the METAR cannot be downloaded, the Next button cannot be pressed until the METAR is provided (re #235)

[István Váradi <ivaradi@…>]

In 6e5ba20962e31d76ed84d216d1ef11aa608690a6:

The deprature METAR is displayed on the takeoff page as well and that and the one on the briefing page are kept in sync (re #235)

[István Váradi <ivaradi@…>]

In db659b771103e9ecf06d04afcccf3e9fd43f444b:

Eliminated some warnings when receiving the signal about inserting a text into the entry (re #235)

[István Váradi <ivaradi@…>]

In 331236ddb60753cce5b97dbed6810b2b585d188a:

Fixed the handling of the 'Forward' buttons (re #235)

[István Váradi <ivaradi@…>]

In f91b10730de0aa863535d63dc21bf409c0f4cd6d:

Added the arrival METAR field to the landing page (re #235)

[István Váradi <ivaradi@…>]

In 214ed755499b096210baa657d61f0f5b4d454bda:

Added tooltips for the METAR fields (re #235)