Phrases are incorrectly splitted between Front-End and Admin language packs

Phrases are incorrectly splitted between Front-End and Admin language packs.

Core
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1. Phrase "lu_ferror_forgotpw_nodata" is located in administrative console's language pack, but it's used only on Front-End on forgot password form.
2. Check all phrases with "lu_" prefix, that are used in admin's php files to checks, that some of them should be moved to front-end language pack.
3. Phrases "lu_PermName_Login_desc", "lu_PermName_Admin_desc" should be renamed to have "la_" prefix.
4. Phrase "lu_no_permissions" should have "la_" prefix, since it's used on both front-end admin.

In-Commerce
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1. Phrases "la_col_Qty", "la_col_QtyBackordered", "la_ItemBackordered", "la_ship_all_together", "la_ship_backorders_upon_avail", "la_ship_backorder_separately", "la_tooltip_New_Coupon", "la_tooltip_New_Discount" should be moved from front-end to admin (keep in in-commerce module).
2. Delete "la_comm_ProductsByManuf" front-end phrase, since it's no longer used.
3. Move "la_fld_Group" (admin) phrase from In-Commerce to Core

[B]MISSING PHRASE:[/B]

1. Missing in Admin->Tools->System Tools section:

la_section_MemoryCache = Memory Cache