Add infrastructure for reading Python command output
Add infrastructure for reading Python command output

This will be used in the future to make tests/assertions for
Python/Haskell codebase equivalence (e.g. checking that the same
opcodes are defined, etc.).

(Side-note: this might not work in VPATH builds; I'll see how it goes)

Signed-off-by: Iustin Pop <acf83a5274f31a43af6b914614365999469c1a31@google.com>
Reviewed-by: Agata Murawska <4c8886dbe342c6966e25105100cfee09458faa93@google.com>

ganeti-github-testing/ganeti-test-1,apyrgio/ganeti,apyrgio/ganeti,yiannist/ganeti,andir/ganeti,yiannist/ganeti,dimara/ganeti,onponomarev/ganeti,bitemyapp/ganeti,dimara/ganeti,ganeti/ganeti,ganeti/ganeti,bitemyapp/ganeti,onponomarev/ganeti,leshchevds/ganeti,mbakke/ganeti,leshchevds/ganeti,andir/ganeti,yiannist/ganeti,mbakke/ganeti,apyrgio/snf-ganeti,leshchevds/ganeti,mbakke/ganeti,andir/ganeti,grnet/snf-ganeti,ganeti-github-testing/ganeti-test-1,apyrgio/snf-ganeti,grnet/snf-ganeti,ganeti/ganeti