Merged in BjoernGruening/galaxy-central-bgruening/requirements (pull request #304)

Add missing requirement tags.

lib/galaxy/datatypes/converters/bam_to_bai.xml

@@ -1,4 +1,7 @@
 <tool id="CONVERTER_Bam_Bai_0" name="Bam to Bai" hidden="true">
+  <requirements>
+      <requirement type="package">samtools</requirement>
+  </requirements>
   <command>samtools index $input1 $output1</command>
   <inputs>
     <page>
@@ -10,4 +13,4 @@
    </outputs>
   <help>
   </help>
-</tool>
+</tool>

lib/galaxy/datatypes/converters/sam_to_bam.xml

@@ -5,6 +5,9 @@
          To fix this: (a) merge sam_to_bam tool in tools with this conversion (like fasta_to_len 
          conversion); and (b) define a datatype-specific way to set converter parameters.
       -->
+    <requirements>
+        <requirement type="package">samtools</requirement>
+    </requirements>
     <command interpreter="python">sam_to_bam.py $input1 $output</command>
     <inputs>
         <param name="input1" type="data" format="sam" label="SAM file"/>