Replace default rm alias with rm function

Define rm to work more like Unix/Linux

* Support -r and -f flags also -rf or -fr
* Support specifying multiple paths to remove

alias.ps1

@@ -2,3 +2,4 @@
 Remove-Item Alias:curl
 Remove-Item Alias:wget
 Remove-Item Alias:cd
+Remove-Item Alias:rm

utils.ps1

@@ -13,4 +13,24 @@ function cd {
   Set-Location -Path $Path
 }
 
-# TODO: Define rm to work with -rf and multiple entries
+function rm {
+  Param (
+    [Parameter(
+      Mandatory=$true,
+      ValueFromRemainingArguments=$true
+    )][string[]]$Paths,
+    [switch]$F,  [switch]$Force,
+    [switch]$R,  [switch]$Recurse,
+    [switch]$RF, [switch]$FR
+  )
+  $Command = "Remove-Item"
+  if ($F -or $Force -or $RF -or $FR) {
+    $Command = "$Command -Force"
+  }
+  if ($R -or $Recurse -or $RF -or $FR) {
+    $Command = "$Command -Recurse"
+  }
+  foreach ($Path in $Paths) {
+    Invoke-Expression -Command "$Command $Path"
+  }
+}