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

Fixes #21
Manage logs when log file is not accessible

Fixes #25

If the default log file location is not accessile, inform user
about the error (e.g., no write permission, location does not
exist). Also, make non-debug log messages shorter and make sure
all instructions and warnings are printed to standard error.
Remove deprecated "--hard" arg. from server reboot