Fix typos and improve INSTALL document

Updated the list of required and optional libraries and tools.
Rewrote the paragraph about the "aux" tools to more accurately
describe what actually gets installed.

INSTALL

@@ -5,34 +5,44 @@ Installing Bro
 Prerequisites
 =============
 
-Bro relies on the following libraries and tools, which need to be installed
+Bro requires the following libraries and tools to be installed
 before you begin:
 
     * CMake 2.6.3 or greater            http://www.cmake.org
 
-    * Libpcap (headers and libraries)   http://www.tcpdump.org
+    * Perl  (used only during the Bro build process)
 
-    * OpenSSL (headers and libraries)   http://www.openssl.org
+    * Libpcap headers and libraries     http://www.tcpdump.org
 
-    * SWIG                              http://www.swig.org
+    * OpenSSL headers and libraries     http://www.openssl.org
+
+    * BIND8 headers and libraries
 
     * Libmagic
 
     * Libz
 
-Bro can make uses of some optional libraries if they are found at
-installation time:
+    * SWIG                              http://www.swig.org
 
-    * LibGeoIP  For geo-locating IP addresses.
-
-Bro also needs the following tools, but on most systems they will
-already come preinstalled:
-
-    * Bash  (For Bro Control).
-    * BIND8 (headers and libraries)
     * Bison (GNU Parser Generator)
+
     * Flex  (Fast Lexical Analyzer)
-    * Perl  (Used only during the Bro build process)
+
+    * Bash  (for BroControl)
+
+
+Bro can make use of some optional libraries and tools if they are found at
+build time:
+
+    * LibGeoIP (for geo-locating IP addresses)
+
+    * gperftools (tcmalloc is used to improve memory and CPU usage)
+
+    * sendmail (for BroControl)
+
+    * ipsumdump (for trace-summary)     http://www.cs.ucla.edu/~kohler/ipsumdump
+
+    * Ruby executable, library, and headers (for Broccoli Ruby bindings)
 
 
 Installation
@@ -44,7 +54,7 @@ To build and install into ``/usr/local/bro``::
     make
     make install
 
-This will first build Bro into a directory inside the distribution
+This will first build Bro in a directory inside the distribution
 called ``build/``, using default build options. It then installs all
 required files into ``/usr/local/bro``, including the Bro binary in
 ``/usr/local/bro/bin/bro``.
@@ -60,22 +70,22 @@ choices unless you are creating such a package.
 Run ``./configure --help`` for more options.
 
 Depending on the Bro package you downloaded, there may be auxiliary
-tools and libraries available in the ``aux/`` directory. All of them
-except for ``aux/bro-aux`` will also be built and installed by doing
-``make install``.  To install the programs that come in the
-``aux/bro-aux`` directory, use ``make install-aux``. There are
+tools and libraries available in the ``aux/`` directory. Some of them
+will be automatically built and installed along with Bro. There are
 ``--disable-*`` options that can be given to the configure script to
-turn off unwanted auxiliary projects.
+turn off unwanted auxiliary projects that would otherwise be installed
+automatically.  Finally, use ``make install-aux`` to install some of
+the other programs that are in the ``aux/bro-aux`` directory.
 
-OpenBSD users, please see our `FAQ
-<http://www.bro-ids.org/documentation/faq.html>` if you are having
+OpenBSD users, please see our FAQ at
+http://www.bro-ids.org/documentation/faq.html if you are having
 problems installing Bro.
 
 Running Bro
 ===========
 
 Bro is a complex program and it takes a bit of time to get familiar
-with it.  A good place for newcomers to start is the Quickstart Guide
+with it.  A good place for newcomers to start is the Quick Start Guide
 at http://www.bro-ids.org/documentation/quickstart.html.
 
 For developers that wish to run Bro directly from the ``build/``

configure

@@ -32,7 +32,7 @@ Usage: $0 [OPTION]... [VAR=VALUE]...
     --enable-perftools-debug use Google's perftools for debugging
     --disable-broccoli     don't build or install the Broccoli library
     --disable-broctl       don't install Broctl
-    --disable-auxtools     don't build or install auxilliary tools
+    --disable-auxtools     don't build or install auxiliary tools
     --disable-python       don't try to build python bindings for broccoli
     --disable-ruby         don't try to build ruby bindings for broccoli