Installed modes are missing files

[nlhowell]

modes.xml includes some modes with install="yes", but the required
files aren't installed.

Some generic suggestions:

• -lexc and -twol modes probably aren't useful to users

• -spell modes should depend on --enable-ospell

• .deps files are never installed, so any modes using them shouldn't be
  installed.

• Messages for package app-dicts/apertium-en-pt-9999:

• Failed to find '/usr/share/apertium/apertium-en-pt/empty.bin' in install image.

• Failed to find '/usr/share/apertium/apertium-en-pt/en-pt-poly.autobil.bin' in install image.

• QA: missing files required for mode en-pt-multi.

• Failed to find '/usr/share/apertium/apertium-en-pt/empty.bin' in install image.

• Failed to find '/usr/share/apertium/apertium-en-pt/pt-en-poly.autobil.bin' in install image.

• QA: missing files required for mode pt-en-multi.