Replace "project" with "project_id" in clients lib

Fixes #24
Fix typo in "load_image_meta" (cmds.image)

Closes #27
Determine authentication errors in CLI init
Conform astakos-CLI commands to kamaki standards

Fixes #22
Enrich CLI errors in "cmds.cyclades"

Refs #21
Enrich CLI errors in "cmds.image"

Refs #21
Enrich CLI errors in "cmds.network"

Refs #21
Enrich CLI errors in "cmds.pithos"
Error decorators preserve decorated method names
Manage project_id errors in all API commands

Refs #21