Mend typo
Remove `upload` with script gone in ee0b7d
Now all architectures can build side-by-side

Base the default BUILDDIR on the result of `$(CC) -dumpmachine` and fix
up the Makefile so parallel builds for different CROSS_COMPILE settings
work.
Remove generated bin/ dir in xilinx/ clobber
Remove needless GENDIR
Mend clobber rule for test/, remove for ex/
Stop referring to GCC as directly
Cosmetics
Install into TOP
Correct `make clean` for BUILDDIR
Update dSYM cleanup in `clean` rule
Search for plugins in the tsim binary path
Add vim modelines
Mend tool path references
Use line buffering for text formats
Be less eager to accept bad input with text format

The text format could eagerly accept the leading portion of a token that
was not a valid hexadecimal string in its entirety. Now `text_in` checks
for whitespace or EOF after the accepted portion, and rejects otherwise.
Simplify and robustify disasm.sh

Now we keep a single instance open as long as it gets valid data (and
restart it once it doesn't). This should improve gtkwave responsiveness
and reduce CPU load. This necessitated the line-buffering of the output
through `tr` and `sed`.

Also shorten strings of leading zeros in hexadecimal constants.
Mend sim clocks
SILENT -> SILENCE (silly mistake)
Introduce a general common Makefile include

Reorganise Makefiles