ecl hangs on multithreaded environment when safety is 0

[dkochmanski]

See #144.

It is not clear whenever it is incorrect declaration or ECL doing weird things on Speed=3/Safety=0.

Steps to reproduce:

1. Modify dependent.lisp file to have safety=0 instead of safety=1
2. Load clim-examples on ecl
3. Try using clim-demo for a while

Expected:

• no problems with event processing

Observed:

• event processing hangs without a reason
• if mcclim uses a single process then problem does not occur

Hang occurs in CLX functions, but they are not always the same, so the reason must be somewhere in: a) a macro for buffer b) incorrect ecl optimization

[dkochmanski]

the problem was caused by an invalid implementation of the conditional-store. See #169.