* change the height of execbar and execibar to be the same as other
bars have by default (6 pixels)
* treat mixer values as percentages as they're usually 0-100 (switch
to spaced_print() with pad_percents)
* change temp_print() from snprintf() to spaced_print()
* remove decimals from temp_print() as none of the current sources can
supply values smaller than 1 degree (C or F, doesn't matter)
* add a space between number and the unit in human_readable()
* fix number printing in human_readable()
* network $upspeed and $downspeed now use human_readable()
This introduces a new configuration variable called "temperature_unit",
specifying the unit of all temperature sensors. To achieve this, each
object outputting a temperature has to call temp_print() like so:
| temp_print(p, p_max_size, <temp val as double>, <unit of val>);
to specify the input temperature unit, either one of the constants
TEMP_CELSIUS or TEMP_FAHRENHEIT.
