Align strings with release

in language.h, but was not renamed here. If TEMP_SENSOR_1 is enabled as redundant then
an error is thrown that MSG_EXTRUDER_SWITCHED_OFF is not defined.

Originaly by @12dstring

Keep "astyled" reformatting

As noted by @darkjavi et.al. in #103, the E1 motor was not being enabled in planner.cpp when using DUAL_X_CARRIAGE. This patch enables and disables E1 as it should.

Add SDEXTRASLOW which runs the SD card at SPI_QUARTER_SPEED. Quarter speed is needed for RIGIDBOT_PANEL

Fix: increased debounce delay.

Replaces #145 which is way out of date

Czech language translation.

Added comment for Czech language (associated with file language_cz.h).

(PR #138)

When the ISR does not finish in time, the timer will
wrap in the computation of the next interrupt time.

This hack replaces the correct (past) time with a time not far in the future.

As noted in #130 allen key probe stow rate is based on homing rates,
but homing rates were left out of most delta configs. This unifies the
XYZ homing rates and applies the unified rates to allen key movements.