many doxygen comments added

install.php

@@ -224,6 +224,13 @@ function main()
     }
 }
 
+/**
+ * checks if an external libary is present
+ *
+ * @param string $external_library Name of library
+ *
+ * @return boolean indicates if library present
+ */
 function haveExternalLibrary($external_library)
 {
     if (isset($external_library['include']) && ! include_once $external_library['include'] ) {
@@ -238,6 +245,11 @@ function haveExternalLibrary($external_library)
     return true;
 }
 
+/**
+ * Check if all is ready for installation
+ *
+ * @return void
+ */
 function checkPrereqs()
 {
     $pass = true;
@@ -295,6 +307,13 @@ function checkPrereqs()
     return $pass;
 }
 
+/**
+ * Checks if a php extension is both installed and loaded
+ *
+ * @param string $name of extension to check
+ *
+ * @return boolean whether extension is installed and loaded
+ */
 function checkExtension($name)
 {
     if (!extension_loaded($name)) {
@@ -305,6 +324,11 @@ function checkExtension($name)
     return true;
 }
 
+/**
+ * Show list of libraries
+ *
+ * @return void
+ */
 function showLibs()
 {
     global $external_libraries;