Merge pull request #998 from urbit/philip/eth-manage

add eth-manage app

app/eth-manage.hoon

@@ -0,0 +1,58 @@
+::  usage:
+::    :eth-manage %look
+::      kick polling from eth mainnet node
+::    :eth-manage [%wind 1.000.000]
+::      rewind to block 1.000.000
+=>  $~  |%
+    ++  move  (pair bone card)
+    ++  card
+      $%  [%turf wire ~]
+          [%vein wire]
+          [%look wire src=(each ship purl:eyre)]
+          [%wind wire p=@ud]
+      ==
+    ++  state
+      $:  a/@
+      ==
+    --
+=,  gall
+|_  $:  hid/bowl
+        state
+    ==
+++  poke
+  |=  [mar=@tas val=*]
+  ^-  (quip move _+>)
+  :_  +>.$
+  ?+  val  ~&(%oops ~)
+      %turf         [ost.hid %turf /hi ~]~
+      %vein         [ost.hid %vein /hi]~
+      [%wind @ud]   [ost.hid %wind /hi +.val]~
+      %look
+    :_  ~
+    =/  pul
+      (need (de-purl:html 'http://eth-mainnet.urbit.org:8545'))
+    [ost.hid %look /hi |+pul]
+  ==
+::
+++  vein
+  |=  [wir/wire =life ven=(map life ring)]
+  ^-  (quip move _+>)
+  ~&  [%pierc life ven]
+  `+>.$
+::
+++  turf
+  |=  [wir/wire pax=(list path)]
+  ^-  (quip move _+>)
+  ~&  [%slurp pax]
+  `+>.$
+::
+++  prep
+  |=  old/(unit noun)
+  ^-  [(list move) _+>.$]
+  ?~  old
+    `+>.$
+  =+  new=((soft state) u.old)
+  ?~  new
+    `+>.$
+  `+>.$(+<+ u.new)
+--