curl nor wget was found
On Centos, to install wget:

sudo yum install wget


To install curl the following should suffice:

sudo yum install php-curl
sudo service httpd restart


++++++++++++++++++++ EDIT +++++++++++++++++++++++++

According to this post, "unable to fork" errors are likely to result from too many processes running.  They recommend increasing the limit like so:

sysctl -w kern.maxprocs=1000000