Hard limits for build and source operations

[zohar]

What needs to be documented?

Not sure we have many limits, but at least for build phase and source operations we seem to have a few hard limits in place and those do not seem to be documented:

• Build timeout (1 hour)
• Build size (8 GB for all containers?)
• Resources use size? (not sure about it)
• No. of parallel builds.

EDIT - removed internal platform.sh info.