Removed unused tables from installer

Fixes installer bug
Removed return from void function

The function is declared void and the return value was not used anywhere
Moved unreachable statement to conditions
Assigments in conditions is often considered bad practice

So let's put a comment, just in case
Method is void, let's not print void
Fixed methods description

These methods were declared void but actually returns values. Added proper documentation.
Typecasting

The GETPOST method returns string, let's make the typecast explicit.
Timestamp is not a type

Timestamps are integers so let's document this correctly
Static members are not always strings

Update method documentation to reflect the mixed type expected
Object type is lowercase
Typo fix
FTP connections are resources

Avoid declaring it as int
PHP doesn't know reals, use float
Text is not a type, let's use string
Wrong var
Developer documentation fix
Update societe.class.php

wrong name of outstandingbill function
Moved unreachable statement
Added class members that where declared dynamically
Codestyle