[3.0] 7c39957 recommend system libjemalloc

[Nils Goroll]

commit 7c399574bedf21a2caebfff59b2cee43fa68aeb0
Author: Nils Goroll <nils.goroll at uplex.de>
Date:   Thu Oct 16 12:04:15 2014 +0200

    recommend system libjemalloc

diff --git a/doc/sphinx/installation/install.rst b/doc/sphinx/installation/install.rst
index 1c6414f..794e938 100644
--- a/doc/sphinx/installation/install.rst
+++ b/doc/sphinx/installation/install.rst
@@ -97,6 +97,10 @@ installed. On a Debian or Ubuntu system these are:
 * libpcre3-dev
 * pkg-config
 
+recommended:
+
+* libjemalloc-dev
+
 Build dependencies on Red Hat / CentOS
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 
@@ -112,6 +116,10 @@ packages installed:
 * pcre-devel
 * pkgconfig
 
+recommended:
+
+* jemalloc-devel
+
 Configuring and compiling
 ~~~~~~~~~~~~~~~~~~~~~~~~~