DOC: amended compilation_faq.md.
- Install tools
```
- (CentOS) sudo yum install gcc gcc-c++ autoconf automake libtool pkgconfig cppunit-devel
+ (CentOS) sudo yum install gcc gcc-c++ make autoconf automake libtool pkgconfig cppunit-devel perl-Test-Harness perl-Test-Simple
(Ubuntu) sudo apt-get install build-essential autoconf automake libtool libcppunit-dev
(OSX) brew install autoconf automake libtool pkg-config cppunit
```
$ wget https://github.com/downloads/libevent/libevent/libevent-2.0.21-stable.tar.gz
$ tar xfz libevent-2.0.21-stable.tar.gz
$ pushd libevent-2.0.21-stable
- $ ./configure
+ $ ./autogen.sh
+ $ ./configure --prefix=/path/to/arcus-directory
$ make
$ sudo make install
$ popd
