Added required development packges.

README

@@ -30,14 +30,7 @@ aria2 is in very early development stage. Currently it has following features:
 * Configuration file support.
 * Download URIs found in a text file or stdin.
 
-3. How to build
----------------
-$ ./configure
-$ make
-
-The executable is aria2c in src directory.
-
-4. Dependency
+3. Dependency
 -------------
 In order to enable HTTPS support, you need GNU TLS or OpenSSL.
 In order to enable BitTorrent support, you need GNU TLS+libgcrypt or OpenSSL.
@@ -54,6 +47,27 @@ In order to enable async DNS support, you need c-ares or ares.
 c-ares: http://daniel.haxx.se/projects/c-ares/
 ares: ftp://athena-dist.mit.edu/pub/ATHENA/ares
 
+4. How to build
+---------------
+In order to build aria2 from the source package, you need following development
+packages(package name may vary depending on the distribution you use):
+
+* libgnutls-dev    (Required for HTTPS, BitTorrent support)
+* libgpg-error-dev (Required for BitTorrent support)
+* libgcrypt-dev    (Required for BitTorrent support)
+* libares-dev      (Required for async DNS support)
+* libxml2-dev      (Required for Metalink support)
+
+You can use libssl-dev instead of libgnutls-dev,libgpg-error-dev,libgcrypt-dev:
+* libssl-dev       (Required for HTTPS, BitTorrent support)
+
+The build process is fairly standard way for *nix programs:
+
+$ ./configure
+$ make
+
+The executable is aria2c in src directory.
+
 5. BitTorrrent
 --------------
 The filename of the downloaded file is determined as follows: