Limited error messages, when selecting the wrong COM port

Hey,

Right now on the Arduino 101 it doesn't give the suggestion to change the COM port when selecting the wrong one. It would be better if it was replaced by this text

Current text:
```
Starting download script...
Flashing is taking longer than expected
Try pressing MASTER_RESET button
ERROR: Timed out waiting for Arduino 101 on COM5
ERROR: Timed out waiting for Arduino 101 on COM5
```

The ERROR message at the bottom could better be something like:

`Couldn't find a Board on the selected port. Check that you have the correct port selected. If it is correct, try pressing the board's reset button after initiating the upload.`

As on this page on line 642: https://github.com/arduino/Arduino/blob/master/arduino-core/src/processing/app/i18n/Resources_en.po

Start by tracing the Arduino 101 upload error for an incorrect COM port and compare the wording at line 642 of arduino-core/src/processing/app/i18n/Resources_en.po. Done means the bottom error uses the suggested message when the selected port is wrong, including the port-selection and reset guidance.

Written by the indexing model from the issue text.