Merge branch 'rh/prompt-tests' into pu
to be broken with older zsh that are still in the field ($gmane/251231).
* rh/prompt-tests:
t9904: new __git_ps1 tests for Zsh
test-lib: make it possible to override how test code is eval'd
lib-prompt-tests.sh: add variable for string that encodes percent in PS1
lib-prompt-tests.sh: put all tests inside a function
t9903: move prompt tests to a new lib-prompt-tests.sh file
t9903: move PS1 color code variable definitions to lib-bash.sh
t9903: include "Bash" in test names via new $shellname var
t9903: run pc mode tests again with PS1 expansion disabled
t9903: move test name prefix to a separate variable
t9903: put the Bash pc mode prompt test cases in a function
t9903: remove Zsh test from the suite of Bash prompt tests