Removes unnecessary Smarty "require" statements
Removes unnecessary LMS "require" statements
Removes unnecessary Auth "require" statements
Reomves unnecessary ExecStack "require" statement
Removes unnecessary Session "require" statements
Reomves unnecessary Sysinfo "require" statements
Removes unnecessary TCPDF "require" statements
Removes unnecessary Ezpdf "require" statements
Removes unnecessary Cpdf "require" statements
Removes unnecessary HTML2PDF "require" statments
Removes by reference DB errors assignment

Strict Standards: Only variables should be assigned by reference
Merge pull request #226 from maciejlew/master

Removes unnecessary "require" statements