snippet(c++): fix or remove duplicate snippets name

Author: kaiwk

c++-mode/const_[]

@@ -1,5 +1,5 @@
 # -*- mode: snippet -*-
-# name: copy
+# name: copy_ostream_iter
 # key: oit
 # --
 std::copy(std::begin(${1:container}), std::end($1), std::ostream_iterator<$2>{

c++-mode/copy_ostream_iter

@@ -1,5 +1,5 @@
 # -*- mode: snippet -*-
-# name: remove
+# name: erase
 # key: erm
 # --
 ${1:container}.erase(std::remove(std::begin($1), std::end($1), $2), std::end($1));

c++-mode/d_operator

@@ -1,5 +1,5 @@
 # -*- mode: snippet -*-
-# name: generate_n
+# name: erase_find_last_not_of
 # key: erf
 # --
 ${1:container}.erase($1.find_last_not_of(" \t\n\r") + 1);

c++-mode/erase

@@ -1,5 +1,5 @@
 # -*- mode: snippet -*-
-# name: transform
+# name: transform-with-closure
 # key: upr
 # --
 std::transform(std::begin(${1:container}), std::end($1), std::begin($1), [](char c) {