Blinkytape with large connected LED count fails on macOS

[cibomahto]

Attempting to control a long (475 LED) strip on PatternPaint under macOS causes the connection to become unreliable, with tons of 'sendChunk: Busy, trying again shortly' messages.

To repeat:

1. Use commit dc19075 on macOS through Qt Creator
2. Run patternpaint, change strip height to 475
3. Open any example pattern
4. Connect strip to computer
5. Strip updates a few frames before stopping

Notes:
-Using MacBook Air 2012 model
-This doesn't seem to affect Windows 10
-In libblinky/blinkytape.cpp, changing 'WRITE_BUSY_DELAY' and 'WRITE_CHUNK_DELAY' to 10 appears to solve the problem

[cibomahto]

Appears to happen when connecting to a tape that is playing a very slow pattern (speed 2). Possibly an issue?