configurable path to toolchain
added gitignore file to ignore compile results
Modified for additional 120MHz Core-Clock
fix delayMicroseconds()

thank you, duff !
Update to 168MHz, 42 MHZ Bus, 28MHz Flash
Fix SPI

Attention, slower SPI
Update README.md
Stripped to overclock add. 144MHz only for Paul
Stripped to 144MHz only for Paul
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fix delayMicroseconds() for 144MHz
Merge pull request #15 from FrankBoesing/144MHz-only

+Overclock 144 MHz only
Add VREF register bit definitions
Add missing DMA channel bits
Use IRQ_PRIORITY (not hard-coded number) in Serial3
Fix lockup in SPI.setDataMode(SPI_MODE0)
USB Mouse on Teensy 3.x to use relative+absolulte hybrid
Support more CPU and bus frequencies