Add tasks for all the new languages

Task/Binary-search/Phix/binary-search-1.phix

@@ -0,0 +1,16 @@
+function binary_search(sequence s, object val, integer low, integer high)
+    integer mid, cmp
+    if high < low then
+        return 0 -- not found
+    else
+        mid = floor( (low + high) / 2 )
+        cmp = compare(s[mid], val)
+        if  cmp > 0 then
+            return binary_search(s, val, low, mid-1)
+        elsif cmp < 0 then
+            return binary_search(s, val, mid+1, high)
+        else
+            return mid
+        end if
+    end if
+end function

Task/Binary-search/Phix/binary-search-2.phix

@@ -0,0 +1,17 @@
+function binary_search(sequence s, object val)
+    integer low, high, mid, cmp
+    low = 1
+    high = length(s)
+    while low <= high do
+        mid = floor( (low + high) / 2 )
+        cmp = compare(s[mid], val)
+        if cmp > 0 then
+            high = mid - 1
+        elsif cmp < 0 then
+            low = mid + 1
+        else
+            return mid
+        end if
+    end while
+    return 0 -- not found
+end function