config: simply config reading and writing logic
config: simply config reading and writing logic

- Treat all global variables, config dicts as readonly immutables
- Don't store anything outside method
- Remove need for first_time variable, checks for file before writing back

Signed-off-by: Rohit Yadav <902b9eb5dd62819678163bd5e00fbf0cbc7c264b@shapeblue.com>

remibergsma/cloudstack-cloudmonkey,apache/cloudstack-cloudmonkey,apache/cloudstack-cloudmonkey,remibergsma/cloudstack-cloudmonkey,Interoute/cloudmonkey-interoute,Interoute/cloudmonkey-interoute