changed the way 'include' attribute paths are resolved in 'small IDEs'

When all the absolute and relative path resolution fail, the topmost enclosing
otp application directory is searched using .app files index, then the file denoted by
include string is searched relatively to the otp app root.

Added tests for introduced changes, modified old tests which were affected by this change.
changed 'include' attribute completion in 'small IDEs'

The completion now honors topmost enclosing otp app directory.
Added tests for the introduced changed, changed old ones to honor the change.
Merge pull request #347 from deadok22/326

include fixes for small IDEs (see #326)