Update posix open() call to incl. permissions
Update posix open() call to incl. permissions

This explicitly grants user read/write access to newly-created mmap files. Previously, on some systems files would be created but could not be re-opened as the user lacked sufficient permissions.
JCavallo/Nim,reactormonk/nim,BlaXpirit/nim,msmith491/Nim,BlaXpirit/nim,fmamud/Nim,douglas-larocca/Nim,sferik/Nim,endragor/Nim,zachaysan/Nim,tmm1/Nim,msmith491/Nim,sferik/Nim,jsanjuas/Nim,russpowers/Nim,douglas-larocca/Nim,bvssvni/Nim,Matt14916/Nim,endragor/Nim,singularperturbation/Nim,Senketsu/Nim,jsanjuas/Nim,judofyr/Nim,zachaysan/Nim,msmith491/Nim,SSPkrolik/Nim,BlaXpirit/nim,nafsaka/Nim,sarvex/Nim-lang,jsanjuas/Nim,Salafit/Nim,nanoant/Nim,dom96/Nim,xland/Nim,BlaXpirit/nim,endragor/Nim,judofyr/Nim,BlaXpirit/nim,gokr/Nim,reactormonk/nim,MrJohz/Nim,fredericksilva/Nim,Salafit/Nim,sarvex/Nim-lang,SSPkrolik/Nim,gokr/Nim,Matt14916/Nim,singularperturbation/Nim,gokr/Nim,Dhertz/Nim,Matt14916/Nim,sarvex/Nim-lang,JCavallo/Nim,haiodo/Nim,zachaysan/Nim,fredericksilva/Nim,Salafit/Nim,zachaysan/Nim,tmm1/Nim,BlaXpirit/nim,tmm1/Nim,fmamud/Nim,jsanjuas/Nim,sferik/Nim,xland/Nim,douglas-larocca/Nim,judofyr/Nim,douglas-larocca/Nim,jsanjuas/Nim,BlaXpirit/nim,jfhg/Nim,SSPkrolik/Nim,jfhg/Nim,nanoant/Nim,zachaysan/Nim,judofyr/Nim,nanoant/Nim,Salafit/Nim,msmith491/Nim,russpowers/Nim,haiodo/Nim,nafsaka/Nim,SSPkrolik/Nim,MrJohz/Nim,BlaXpirit/nim,douglas-larocca/Nim,sferik/Nim,sferik/Nim,nanoant/Nim,tulayang/Nim,Dhertz/Nim,russpowers/Nim,Senketsu/Nim,judofyr/Nim,Senketsu/Nim,MrJohz/Nim,tulayang/Nim,kirbyfan64/Nim,msmith491/Nim,Matt14916/Nim,JCavallo/Nim,haiodo/Nim,nimLuckyBull/Nim,Salafit/Nim,haiodo/Nim,greyanubis/Nim,xland/Nim,sarvex/Nim-lang,mbaulch/Nim,Matt14916/Nim,mbaulch/Nim,jfhg/Nim,msmith491/Nim,nimLuckyBull/Nim,endragor/Nim,msmith491/Nim,jfhg/Nim,russpowers/Nim,zachaysan/Nim,kirbyfan64/Nim,singularperturbation/Nim,nimLuckyBull/Nim,zachaysan/Nim,russpowers/Nim,SSPkrolik/Nim,douglas-larocca/Nim,dom96/Nim,judofyr/Nim,fredericksilva/Nim,tulayang/Nim,gokr/Nim,dom96/Nim,xland/Nim,russpowers/Nim,fredericksilva/Nim,tulayang/Nim,fredericksilva/Nim,fredericksilva/Nim,tulayang/Nim,nafsaka/Nim,fmamud/Nim,endragor/Nim,nimLuckyBull/Nim,JCavallo/Nim,Senketsu/Nim,mbaulch/Nim,fmamud/Nim,bvssvni/Nim,nafsaka/Nim,fmamud/Nim,sferik/Nim,nanoant/Nim,tmm1/Nim,endragor/Nim,nimLuckyBull/Nim,nimLuckyBull/Nim,JCavallo/Nim,dom96/Nim,kirbyfan64/Nim,greyanubis/Nim,MrJohz/Nim,kirbyfan64/Nim,SSPkrolik/Nim,greyanubis/Nim,reactormonk/nim,nimLuckyBull/Nim,nafsaka/Nim,singularperturbation/Nim,MrJohz/Nim,jfhg/Nim,haiodo/Nim,xland/Nim,kirbyfan64/Nim,sferik/Nim,JCavallo/Nim,singularperturbation/Nim,Matt14916/Nim,Salafit/Nim,reactormonk/nim,gokr/Nim,mbaulch/Nim,bvssvni/Nim,douglas-larocca/Nim,haiodo/Nim,mbaulch/Nim,sarvex/Nim-lang,bvssvni/Nim,SSPkrolik/Nim,kirbyfan64/Nim,dom96/Nim,nanoant/Nim,greyanubis/Nim,tulayang/Nim,judofyr/Nim,gokr/Nim,dom96/Nim,kirbyfan64/Nim,mbaulch/Nim,Senketsu/Nim,greyanubis/Nim,jsanjuas/Nim,douglas-larocca/Nim,nafsaka/Nim,sarvex/Nim-lang,MrJohz/Nim,Senketsu/Nim,greyanubis/Nim,sferik/Nim,bvssvni/Nim,jfhg/Nim,tmm1/Nim,jsanjuas/Nim,fmamud/Nim,reactormonk/nim,Dhertz/Nim,kirbyfan64/Nim,gokr/Nim,greyanubis/Nim,xland/Nim,Dhertz/Nim,judofyr/Nim,haiodo/Nim,tmm1/Nim,reactormonk/nim,reactormonk/nim,endragor/Nim,JCavallo/Nim,fredericksilva/Nim,reactormonk/nim,gokr/Nim,singularperturbation/Nim,tmm1/Nim,Matt14916/Nim,russpowers/Nim,MrJohz/Nim,Dhertz/Nim,singularperturbation/Nim,nafsaka/Nim,bvssvni/Nim,Senketsu/Nim,bvssvni/Nim,xland/Nim,fredericksilva/Nim,jfhg/Nim,sarvex/Nim-lang,Salafit/Nim,Dhertz/Nim,fmamud/Nim,SSPkrolik/Nim,Dhertz/Nim,nanoant/Nim,dom96/Nim,mbaulch/Nim