[FIX] Solve some mail issues which are currently present in 7.0
[FIX] stock: remove permission to create locations for partner managers

There's a big risk of mistake with the fast-create
feature and they don't need it

(Rebase of PR #1073)
Merge pull request #724 from odoo-dev/7.0-mail_issues-fix-adh

[FIX] mail: misc bug fixing
- avoid deleting the Whole Company mail group if still present, because it is required for some module installation. In 7.0 installing some modules may crash if this group is not present.
- fixed an issue when computing possible recipients in the Chatter
- small fix in html2plaintext about blank lines
[FIX] orm: custom m2m with different label

At rev 84e9a67cdf78db94cb7a09543c1b7ac4ad19d8b4 a check to avoid the creation of ir.model.relation for custom modules was added. The condition is not correct as based on the string instead of the field name. We do not have access to column name at this level but the the m2m relation table do start with x_ for custom fields (see __init__ method).
[FIX] hr: call hr_employee super's when unlinking

Also fixes some weird inheritance bugs in upper versions
[FIX] event_sale: reset event-related fields on SO line when switching products
[FIX] l10n_lu: taxes (amont/aval)

The accounts "TVA en amont" were not used by the l10n_lu chart of accounts.

Instead the accounts "TVA en aval" were used for all taxes both sale and purchase taxes.

(Manual rebase of PR #735)
[FIX] l10n_lu: wrong mapping of accounts to P&L financial report

Account 655 and its child 6554 were both mapped.
Fixed by unmapping 655 and mapping all its direct children.

(Manual rebase of PR #733)
[FIX] tools: mail: fixed last commit, solving an issue with the html2plaintext introduced another issue with notes. Reverting to the first version.
[FIX] ir_values: fallback when no condition

When searching for default values, if we set a condition (e.g. 'type=out_invoice'), fetch also the default values without any condition set. Thanks to the order by clause, the one with a condition have an higher priority than the one without and will not affect existing result.
This fixes default journal/currency on an invoice where the journal is retrieved in the onchange_company_id method (domain is forced). Without this patch only ir.values with a domain set will match, opw 610645
[FIX] hr_timesheet: missing '&' in domain clause

To search the contracts for payroll, the domain is constructed with three clauses. Each of these clauses needs to start with a '&' to make sure they are correctly combined with the OR clause'
[FIX] crm : propagate the lead_id when scheldule other phone calls
[FIX] procurement: avoid to run multiple scheduler

Avoid to run the procurement scheduler multiple times in the same time, otherwise, they tend to interfere with each others
[FIX] account: better error message when regenarating opening entries (opw 606923)

If we try to generate twice entries on the same fiscal year, we can get completly unrelated errors ("You can only reconcile journal items with the same partner").
With this, we make sure people will first cancel the entries before regeneraing the entries.
[FIX] sale: only propose services for pay advances

When creating an invoice from a sale order, if the user choose to invoice a fixed price (deposit), he has the possibility to choose an advance product. As described in the help message, this product should be a service product. Therefore, we add a domain so only services are displayed in the dropdown list