improved docs
fixed typo
added missing UT reference
updated todo
updated todo
fixed bug: \addplot[stack plots=false] used to work up to 1.8, but failed until now. Fixed.
fixed some broken tests and added new one

The broken tests were due to a wrong decision to load a compatibility
layer FPU file: it then loaded the old FPU which is no longer compatible
with the current PGF CVS
updated todo
updated wrong references after I moved tag 1.11
Merge branch 'master' into stable

Conflicts:
	source/latex/pgfplots/pgfplotstest/regressiontests/unittest_external_make.checkoutreferencerev.sh
- improved syntax for 'intersection segments': added 1-based indices
added regression test
fixed bug: hist/density was broken since some time
updated todo
fixed missing character warning
adopted changelog
improved test scripts
adopted clean target
updated makefile
fixed bug in 'point meta/symbolic={}': it should expand results