Update the CHANGELOG file and fix a link in INSTALL

Movim 0.8.1 - Polar Aurora

Movim 0.8 - Polar Aurora

Movim 0.7.2 - Sandstorm

Movim 0.7.1 - Sandstorm

Movim 0.7 - Sandstorm

Movim 0.6.1 - Cumulus

Movim 0.6 - Cumulus

- Merge with edhelas

Increased Session timeout.