Fix bug in error detection code, where a zero-length string was causing a traceback

Fixes #5064
Fixes #5056 Append new hosts to the groups cache
fix heading name syntax in AWS guide
Avoid a traceback when using accelerate

This bit of code is attempting to access accelerate_inventory_host,
which may not have been set/created. This will cause a traceback.
Instead use getattr with a fallback to False.
Fixes #5030 compare connection user and sudo user and disable sudo if identical
Merge pull request #5085 from tgerla/awsfixes

fix heading name syntax in AWS guide
Merge pull request #5086 from j2sol/fix-accelerate_inventory

Avoid a traceback when using accelerate
Add release history for 1.4.1 into 1.5 branch.
Correct the invocation of ‘_assemble_from_fragments’
Docs: Fix the module formatter code that is intended to remove the 'historical' variable from showing up in version_added information (RST)
No longer need to reference 'version_added' in docs for these, as this was quite a while ago.
There's a cleaner way to do this, commit to module formatter pending.

Revert "No longer need to reference 'version_added' in docs for these, as this was quite a while ago."

This reverts commit ff0a41d446a03f93aa57a6baa96c5333bea269ea.
Code to limit display of version_added attributions in modules for modules that are too old to call out this information.

This does not generically apply to new arguments added to existing modules, just the version_added attribute on the top level modules.
Update the .gitignore based on the docsite restructuring.
Merge pull request #5088 from EspadaV8/5057_assemble_fix

Correct the invocation of ‘_assemble_from_fragments’
Fix traceback in template error detection code

Fixes #5081