Resolve "More resilient student lookup in MOSES"

Closes #5

See merge request !3

Resolve "moses tool: extended info; exception - list index out of range"

Closes #4

See merge request !2

update parameters to retrieve extended info

See merge request !1

fix args issue
fix language issue for english courses

 * no pw is supplied
 * no pw can be found in the keychain
 * --store-credentials is not given

the tool will now ask if the pw should be saved.