use tep_db_fetch_array() to get tep_db_query() results
module install() now starts fresh via initial call to remove()
changed _POST references to use HTTP_POST_VARS
changed _GET references to use HTTP_GET_VARS
fixed error message from showing up when laying invoice order and handling_fee module not installed
now uses tep_db_fetch_array() in sveawebpay_config as well
Revert "changed _POST references to use HTTP_POST_VARS"

This reverts commit 2749e16b6f8c9fa42afcadba32a2b354f9239018.
Revert "changed _GET references to use HTTP_GET_VARS"

This reverts commit 2493c3fd3df2906ab08e69fb8b2538e5e641fc82.
fix for division by zero if handling fee currency missing
cleanup
Added note on osCommerce, PHP versions tested.
uppdated info.json to reflect latest module version compatibility
bumped version to 5.2.0
removed integration package 1.6.1 files
added integration package 1.6.3 files
Merge branch 'feature/compatibility_release' into develop